Sorry for the long wait! This video took over 80 hours to produce, a good chunk of which was in the animated sketch at 40:12 . I'm particularly proud of the animated trees which are entirely my creation (the tornado is green screen.. not quite at that level of skill.. yet) - a simple thing to a professional animator but like summitting Mt. Everest for a novice like me. Okay, okay, a HUGE chunk of that production time was having to learn programming an Altair 8800 the hard way. The confusion of having dual purpose data/address entry switches and tiptoeing around octal took me down some seriously deep rabbit holes, and I am indebted to the very patient members of the vcfed.org forums for helping pull me out! Have I told you I suck at math? I suck at math. An epiphany that hit while I was working on this and biting my nails over how long it was taking: I think I'm kind of done even trying to chase the algorithm. I'd rather not have the pressure of a schedule, so I can focus on making art. I really enjoy that last 10% of the process, when the main editing slog is done, and now I get to spice things up with a salty Robot TV director or get blown up turning on my Altair. Too often I've had to short circuit that to hit a self-imposed deadline, because, gasp, it's been 2 whole weeks since I last uploaded! I've done a lot of thinking and my preference is to just make the best quality video I can while still having a life outside of work (video editing most definitely is work, sometimes it feels pretty close to The Hot Place). If it takes 2 weeks to make a video at a sane pace, great, if it takes 6 weeks, so be it. The channel recently hit 2 million views and I am absolutely blown away that my creations have been viewed that many times! Thanks to all of you for your support, be it just viewing, sending a positive comment, or joining my small but awesome Patreon crew. Hope you enjoy watching this video as much as I enjoyed making it! Cheers! PS: Special thanks to my daughter Jacqueline for colorizing the Altair drawing from the MITS manual, as well as Steve Dompier's "Altair Music" sketch! I don't know if either ever existed in color but if they did I think she probably got pretty close to what they would have looked like!
The front panel switches are mapped in octal because that is the way the 8080's instructions are decoded. It makes it much easier to memorize all of the binary opcodes because you only need to learn a simple pattern, rather than all of the 256 possible codes. The upper two bits define the type of operation. The two lower 3 bit groups are the parameters specific to the type of operations. Our early assembler was offsite on a timeshare machine. Programs came on paper tape. We had a paper tape loader in ROM. I did many program patches via a switch panel, as a reassembly was a laborious processs that involved punch cards and a trip downtown. It was handy to have the instruction set memorized. Thanks for the video.
That's interesting - the explanation for Octal, that is. What's even more interesting is that the Intel data books on the 8080, 8085, and the 8086/88 were all in hex, and every assembler I've ever used for these processors was in hex. You were not expected to memorize the specific field definitions for the op-codes, but simply know that something like 0x2ef8 was the opcode for "X", and the fact that 0x2ef9 was "X immediate" wasn't really relevant. At least in the contexts I was working within. The only time I was concerned about bit-fields was when I was packing data for a specialized I/O chip or masking out flags in the status register.
Yes, the move instruction was based on 0x40, and the register or memory was based on 0x80. Then the registers were b, c, d, e, h, l m and a (0-7) (m was indirect (hl)). The ops were add, adc, sub, sbb, ana, xra, ora and cmp (0-7). Thus fully 1/2 of the 256 instructions were spoken for. If you look at a map of the instruction set, the middle is occupied with these instructions. And their layout makes sense in octal, 2 bits, 3 bits, and 3 bits. Intel was not trying to make the processor fit octal, it just happened to make sense. The cpu had no multiply or divide instructions. We had no assemblers at first, and so memorized the instruction set by heart. I hand wrote listings and hand assembled them, writing the opcodes down from memory on the left side, then I would enter the program. We learned how multiply and divide worked by making routines that used bc, de, and hl to shift and add or subtract to make it work. I think you can't imagine today what excitement there was at the time both building the machines from scratch and making them do what you wanted. I program complex routines in C and C++ and write drivers for Linux, but I learned %90 of programming back in those days.
I learned BASIC in Mr. Dyk's class in 1976 on 2 16K Altair 8800a micros, one with an ADM3 terminal and the other with a teletype 33. We also formed an after school computer club and made a computer dating service. The story on page 8 of MITS Computer Notes for July, 1977.
@@belstar1128 yes, Mr. Dyk had the foresight to put his students on the leading edge of technology. Before then we used punched cards to send our FORTRAN programs to a computer across town.
My first job was working in an Altair store. Since they only came as kits, I assembled them in order to sell complete computers. I also programmed them some. I always liked them and thought they were well built, but couldnt afford one (bought a TRS-80 instead, about 1/5 the cost). But I figured over time the value would drop as they became obsolete and I could pick one up at a techie flea market (Dayton HamVention, for example) for not much. Never happened. They were expensive in 1976, never went down and they still are expensive today.
Yeah.. I kept passing on 8800s that were selling for less than $2k for years because I thought it was outrageous. And then suddenly it wasn't. I still wonder if my Altair's deficiencies were the reason for the low price, or if I just got extremely lucky because a bunch of potential bidders didn't want to fork over $6k just after Christmas and stood down.
Great video. Seeing your old Altar playing music was fun to watch. I have two IMSAI 8080's and two or three other S-100 buss based computers. My IMSAI's are a hodgepodge of cards inside, and the power supplies are over-designed linear tanks. I have them running two different operating systems. One is a custom OS design based on NorthStar DOS and the other is called ZRDOS, or Z-80 Replacement DOS (a Z-80 replacement for cp/m, which was designed for the 8080), custom BIOS, with the user interface of ZCPR3. Both systems use the Cromico ZPU. One of them runs both 8 and 5-1/4-inch floppies with a 20meg SCSI hard drive, and the requisite serial terminal. My second IMSAI is just a basic computer. Front panel programmed to boot. I think it's my favorite.
A friend of mine from college built his own S100 bus computer. He had a mix of boards from Altairs, Processor Tech, Imsai, and a few others. He had a slightly burned up front panel board from an Imsai, that needed a lot of repair. The board had bad chips, burned or missing traces, and a lot of bodge wires from repair attempts, He studied the schematics of both the Altair and Imsai panels, and then drew up his own simplified version. He replaced lots of triple and quadruple NAND, AND, NOR, and OR gates with diode wire OR arrays and inverters. In a few places he used discrete transistors. His Frankenstein panel worked as well as the Imsai one did, and he even added a few extra features. He found a bunch of static 22 pin ram chips that would almost be a pin for pin drop in for the 22 pin drams MITS attempted to use on their DOA 4k ram board. He also modded a second MITs 4K dram board to use the refresh the drams using the Z80's refresh signals (after he replaced the 8080 cpu card with a "ZPU" card.) His power supply used surplus transformers and capacitors (totalling almost HALF a FARAD for the 8v line). The thing could have powered and ARC WELDER. I worked at a small computer store in Manhattan while in college. The owner was literally a hippy, ex musician. I built SWTPC kits for customers that wanted them assembled. I also repaired bad memory boards that kit builders couldn't get to work. Most of the time the problem was a small short on the PCB where it hadn't been etched enough. I got pretty good finding faults with a cheap oscilloscope, logic probe, and a DMM.
I have sold the Altair 8800 on eBay for $10,000 - the record to date as of this post. I took a selfie with it for fun and posterity. I really appriciate the time and care you put into making this video.
Very cool. I was only 12 years old when I saw this on Popular Electronics and I wanted one so badly that I started learning electronics. By the time I was 15 I'd built an 8080a system that never fully worked - but the 2102 static RAM (1Kx1x8) board I build *did* work and I still have it. BTW: your production values are great and unique. Love this video and I'm subscribing and digging through your previous videos. Best wishes and Continued Success!
@@TechTimeTraveller No, I soldered wires. It was kludgy. Here's the 1Kx8 Memory Card. It has eight 2102 (1K x 1bit) Static Ram chips. A labor of love. agilefrontiers.com/assets/images/memory-1k.jpg
A computer that I ran into that predates the Altair by 2 years is the French made Micral-N which was manufactured back in 1973 and makes you think that the Altair 880 was modeled after it.. It also seems to have come out before the MCM which was WAY AHEAD of it's time !!!
Using AM radios to play music is a trick that goes back a lot farther. I remember seeing PDP-8s doing it. It’s amazing the patience to come up with the right sequence of instructions to get the various tones.
Yes! I'd love to find a video of a PDP-8 or such doing it. As far as I know the Altair was first as a 'home computer', although who knows what experimentation people got up to with machines that came prior. I can't even imagine how Steve Dompier figured his music out! Way more patience than I have!
If we go back even further the TX-2 was the first via. a slightly different mechanism, but the concept of using a loop to produce a square-wave at a given frequency was well understood by the time of the Altair.
Stumbled on your channel by chance. I’m from U.K. and grew up with Sinclair computers in the 80’s great interesting video and well explained. I’m gonna subscribe and watch more of your content . Thanks Aron
This is the first video of yours I've come across and as a hardware geek this has the be the most in depth look at an 8800 I have seen so far, most videos I have found just show a quick glance inside and then go off on the history of it. Cheers for sharing all the model and internal info all in one place!
I built an Altair 8800 in 1976, while still in High School.. I eventually got (2) 8” floppy drives for it, with a Tarbell controller, and got it to run CP/M.. next came a 600 baud modem, and CBBS software (dial up bulletin board system)… ah, memories. with all of that said, I’d recomend one of the $300 clones, such as the Altair Duino, has the front panel a simulates the 8080, its enough to run CP/M, Altair Basic etc.
As always love your sense of humor in your videos. It's awesome that you were able to obtain what's normally unobtainium. Here in the Philippines, it's even harder to look for vintage computers and ordering them from the US, Canada or Europe usually kills most of the budget with shipping costs.
Many thanks! I just saw a machine with a higher serial than mine sell for $6700 today (ulp). And yes shipping would be horribly expensive given how heavy they are!
it's hard to find anything vintage reasonably in thailand too. like even just 90s and early '00s era pc's. latter half of '00s and onwards you can just go to an it mall and pick up though.
Amazing, you brought up the Mark 8. My dad kitted it for the hobbyist market. Indeed, there was a user group called the Hal Singer User Group which was centered around the Mark 8. He was a part of that. My father then went on to the Homebrew Computer Club where he was at the first meeting and worked with Apple back then.
That's awesome.. so by 'kitting', you mean he was providing it with additional parts beyond the board? My dream is to find some original copies of Hal's newsletters to have Grant Runyan's published words there. I know they're available online but something special about the original paper copies. I wonder if your Dad ever ran into Grant in their travels! Did your dad keep his Mark-8?
Years ago, I had one of the dual drive units. I think I paid $25 for it at a ham fest. There was nothing inside except for the power supply. I outfitted with a Morrow Wonderbuss, Intercontinental Micro s-100 single board, two 35 track dual side dual density drives, hooked up external 8" drives, external SASI 10mb drive, and used it as a development machine for years. Later, I stripped out the single s-100 board, and sold the MITS case for $250 to someone who wanted it as a collectible.
Darn! Yeah that's the story of many an upgrade. I curse myself for all the things I've tossed over the years. The Foley really seems to be super rare.. but I don't think I've seen on get near a Rev 0 value wise so still potentially attainable unless the market has changed.
I'm glad you mentioned Deramp I've been subbed to his channel for years now and he's why I have enough of on interest in the Altair as an actual computer to be seriously considering getting one at some point or building out a clone. I've nearly bought an 8800A more than once because they pop up working for so cheap because so many collectors don't want them for what ever reason. I've also considered just building a clone to get my Altair fix but it's around the same price as just picking up an 8800A but most the clones have the added advantage of being easily to swap into full S-100 bus machine if you want that.
Mike is a great guy, he has a natural talent for explaining tech. I've watched his Altair videos multiple times. His clone was really cool too.. I regret not buying one when they were for sale. And I agree I think the 8800a would be a great buy.. not as expensive as either the 8800 or 8800b, better power supply but still the essence of an Altair.
Yeah for me it's more about capturing the essence of the machine, it's also why I'm more willing to do stuff like PSU rebuilds on old machines than some folks are. It also helps I'm acutely aware of how easy it is for those old power supplies to blow and take out the machine with it and to me preserving the machine overall is more important that something relatively inconsequential as replacing the power supply especially when I know something like an 8800 I'll explore and use enough that the power supply failing is a serious concern.
Fabulous stuff, Brad! The time and effort you put into these videos really shows and is appreciated. The demonstration of the origins of computer music was really excellent - I'd read about it but now I've heard it! Wishing you and yours a great Christmas and new year!
Many thanks! I am trying hard to stick to a quality over quantity approach. It's hard sometimes because RUclips makes it competitive.. they're always guilting you with stats and showing you other youtubers in your niche who are rocketing past you. But I think the time taken here really paid off well and let me add things and fix more bugs. Thanks for the high compliment and glad you enjoyed it!
37:17 it looks like it wraps on overflow rather than saturates. That's good, it's what most processors do, some rely on it, for example if you keep adding 1 to a counter you usually want it to wrap around and keep counting rather than just stop counting
Fun fact: the same company also made an audio amplifier. I have one, and it has the same font on the faceplate that it is on Altair. It's not particularly good or bad, but it looks cool.
I can tell you what happened with the D7 bit being set by mistake on your addition program. The 8080 (much like the derivative z80) has a carry flag to facilitate doing 16 bit additions. In your case the carry flag would have been set and the rest of the addition goes on as expected.
Early micro computers were built to resemble mini computers like the PDP8 and PDP11 made by DEC. Since DEC used Octal notation, early micro computers followed that. The Intel 8080 instruction set actually did group bits into two 3 bit and one 2 bit combination when decoding the instructions, so it did make sense to describe the instruction set in octal. Later micro processors didn't follow this, the Motorola 6800 instruction set was listed in hexadecimal.
@@jgunther3398 Intel's first documentation on the 8080 broke the instruction set up into octal digits when showing the encoding. Later instruction set listings were in hex. The z80 had a super set of the 8080 instructions. Mostly they used unimplemented 8080 opcodes as leadin bytes to change the operation of instructions. For example, one set of leadin bytes caused the instruction to use the IX or IY index register instead of the HL pair.
@@jgunther3398 The 8008 and 8080 opcodes are ordered in such a way that various bit combinations are in groups of 3. The basic MOV, LD, ADD, SUB, and similar instructions that specify a register can be represented in octal. This was obvious when you looked at the opcode charts with the binary groupings. However, Intel did list the entire opcode set in Hexadecimal. If you were programming the Altair from the front panel in "Machine Code", you might prefer to think of the bit patterns in Octal. However, if you were entering the code from an assembly listing, you might prefer to us Hexadecimal. Addresses made more sense to show in Hex rather than "split octal" The other reason that Octal was popular was that the DEC PDP-8 panel was in octal, and many programmers cut their eye teeth on a PDP8.
I always love coverage of the MCM-70 that ran a version of APL so it could get the most out of its extremely limited capabilities. It would have been differently interesting if it ran Forth, but APL actually had IBM backing. Computers could be so weird back then!
I’ve only seen one at the Computer History Museum in Mountain View. I expect there are so few that they will all need to be handled institutionally. I think the best the public will get is some kind of emulator on BitSavers.
Killer Find, The Mixed bag means Notta! I've yet to this day bring myself to spend the money on myself and build a new PC from the ground up. a Kid in the 80s & 90s, everything I had was Trash picked or Flea market cheap finds into my mish-mash WiteBoxes until I had something that would finally install Dos LOL
In a professional environment, I worked with two different S-100, Cromemco systems. The first was a Z80 computer designed for doing weather graphics. It was called a ColorGraphics LiveLine II. I think it used a Dazzler card, a DEC VT100 terminal, a 10MB hard drive, and a GTCO tablet. An 8-bit rudimentary graphics system used for broadcast meteorologists for their presentations. I couple of years later I was using a ColorGraphics ArtStar 3D Plus. It was a 24 bit true color system, but still based on an S-100 bus. The CPU was now a Moto 68020, and instead of CP/M, it ran a UNIX clone called CROMIX. Even with the 68000 based CPU, I saw references to Z80 in the files on the system. Oh yeah, this thing had a massive 200MB hard drive! I have some demo videos of the ArtStar, here on RUclips. It's what I learned 3D animation on, for better or worse. The ArtStar was also sold as a weather graphics system, called the LiveLine V. It even had a bit-slice processor!
I remember seeing the ad for this when I was in high school (I graduated in '75). I was dismayed at the price because it was well out of my reach. It was not clear to me what it could do that was actually useful. I had previous computer experience. Our sixth-grade class helped beta-test the Plato Learning System on the Illiac at the university through terminals connected to the big machine across town. It wasn't obvious that this could be connected to a terminal (and then there would be the additional cost for a terminal!). But I had been playing with binary numbers on my own for six years just because I figured it might be important, so the switches and lights on the front panel weren't completely alien to me. I'm delighted to hear the music from your radio. I remember seeing all the ads for the S-100 bus systems in Creative Computing. I didn't realize that bus originated with the Altair and I forgot that Microsoft basically got started selling BASIC (that they stole from Dartmouth) for the Altair. Much fun! Thank you very much!
I look forward to your new videos so much, regardless of how long between uploads you need to get things to a point you’re happy with. Thanks for teaching me so much about these old machines!
@@TechTimeTraveller I grew up in the C64 era and these older-than-me machines fascinate me so much. Most of what you demonstrated was a little beyond me but made me glad I bought an Imsai 8080 replica to play with. Now, what to do exactly... 🤔
37:49 To explain this a little bit if you are curious. When you have an overflow it rolls over to 0 in the sense that 377 octal + 1 = 0. If you are adding more than that it continues past 0. You can think of it like an odometer rolling over in a car. Basically computers add binary digits from right to left. so basically it did add 2 + 3 to get 5 like you said. Then it went on to add all the 0 bits to get 0s. Then it added the last two 1s and got 10 binary. The 0 gets saved in D7 and the 1 ends up in the carry flag never to be heard from again. Overflows go off the end and whatever was the result of the lower bits is what is saved.
That was awesome. So much to like about this video. You must have been over the moon when you got the audio happening, Media player today, Doom tomorrow
Thank you! I've always been into history and this hobby is one of a few things that can really transport you back, especially in my 1970s era house. The music sequence really brought the era to life for someone who missed it as a child.
The world's first home computer music was radio interference? Damn. I guess I know where the FCC getting all militant about RF radiation in the late 1970s came from....
CAn only agree about the Christmas thing. I came into possession of a DEC digital Server with a Pentium Pro inside, just today. Because of a lowball "nah I am gonna be outbid anyway" offer I made on December 20th. got it for less than half the price that these machines usually command.
Oh my gosh, of course you're an Edsel guy. 🙄 I'm just kidding, all of the Edsel guys I know are decades older than me, but I love listing to them rattle on about old technology and mechanical stuffs. Still don't understand what they see in cars that look like that though. Awesome video, it was very much worth the effort!
Lol don't worry I ask myself that question every day now that I'm out. Obviously was too young when they were new. They're actually kinda restrained compared to other late 50s cars.. basically just Fords with a weird grille. I guess I like oddball/unloved stuff. And the Teletouch electric gear selection system. But it was one money draining hobby too many. Thanks so much for watching!!
Once upon a time, using the TRS-80 Model 3 and/or Model 4, there was a game (something about ghosts) that play wild and perfect music through a nearby AM radio. It was fully intentional, and done really really well. Probably till have these old computers kicking around in the basement. Maybe... Quite a few years ago we visited a little one-man Computer Museum in Annapolis Royal, Nova Scotia. He had all sorts of amazingly early hardware, including the "first" PC, one of those from before the Altair. Had some super-early Apple hardware. All sorts of things.
Micro Instrumentation and Telemetry Systems (MITS) - Ed Roberts and Forrest Mims founded MITS in December 1969 to produce miniaturized telemetry modules for model rockets such as a roll rate sensor.
Fantastic stuff - you've earned a subscriber! I will openly admit that this era of computing doesn't interest me that much, just as I'm sure the 90s era I'm interested by doesn't appeal to others... But, your presentation and passion for this is wonderful and this was a fun watch! I do love just how basic these machines are - there's something so satisfying about seeing PCB traces that were drawn by hand.
The only time I ever saw an Altair was in a locked, glass-fronted computer room in the old DeVry Institute of Technology Chicago location when they were focused on electronics degrees only. A few years back! Thanks for the memories.
Great opening!! So cool that you got one. If I'm ever "rich" I want to get one :) A while back I saw a Altair 680 on eBay for $4k. I had never heard of that one!!
Thanks for this riveting video and the trip to the past. Although I'm old enough to have used an Altair 8800, I haven't had this chance. The first computer I have put my hands on was the French-made MBC Alcyane, which was much inspired from the Altair to say the least. It wasn't a hobbyist machine though and not mine either, but belonged to a computer club. A big difference (and improvement IMO) is that switches were in groups of four, hence hexadecimal was being used 😁
@@TechTimeTravellerOne reason it was so awesome, besides the work that originally went into figuring it out, but what you said... a radio probably was the 1st peripheral for the Altair and thus the 1st ever Personal Computer.
4:58 That brings back a flood of memories. I couldn't afford one of these but I did build the Cosmac Elf in that time frame. Too bad our house burned down about a week after I finished building it.
I love these blinkenlights boxes, thanks for coming up with these introductions. Because I can´t even afford a broken C64 I can at least by You gaze at this very interesting stuff. And for an old stuff guy You not listening to radio anymore feels wrong. I love and still use fm radio all day, i grew up with radio, it was my window to the world (with all the different wave ranges)- I spent a lot of time in front of the dial as short and medium wave were still very propagated in the 70´s West Germany. Anyway: a special thanks for that analog digital music, if I was living in the States I´d be itchy to come over and take a deeper look into different melodies and a better sounding recording. Maybe find the sending part and couple directly into it? Have a beautiful Christmas, it is a nice blinkenlight bleep bloop box!
Where I live we only get a few stations.. mostly general listening stuff and I'm not a big fan of most current music. I was a huge radio listener when I lived near Toronto, so many great stations. But here our main station is a tourist serving outfit that plays the same songs over and over and over again until you hate them. So I've resorted to ipod or phone use. I do hear radio when driving with my wife now and then. I did want to do more songs but it takes SO long to enter programs on the Altair front panel, and with old machines I get worried about stuff failing. The fan on my Altair isn't very effective and I have no idea how good the workmanship was on this PSU. But it didn't really give me any problems so maybe I'll be more adventurous. In my next video on it someday I'm hoping to connect to a teletype I have and try stuff like BASIC programming. Maybe I'll add new music too! Have a great Christmas too! 🎄
Thanks really enjoyed your video. Brought back fun memories of my work in the 70s and 80s fat fingering in a program on a mini computer. Starting the computer you would fat Finger in a program that would allow you to read a paper tape on a teletype and the paper tape would load in a program that could then read from magnetic tape that you could then install your operating system, etc..
The front panel is binary, it's just grouped as octal numbers. I don't get the need for all the references to octal. If the input were truly octal you would have 5, eight position switches. But you don't, it's just groups of 3 bits.
Yeah I didn't explain that real well. I suppose I should have said, the switches and lights are binary, but MITS grouped them to correspond with octal notation, which is easier than binary numbers for humans to work with/remember?
Shortly after the Altair came out my college roommate assembled one. It was tough to get working (I remember something about him sitting in a dark room looking for a very pale trace on an oscilloscope). I was the software guy, much like you my first program adding 3 plus 4 to get 7. Later I wrote my own flashing light patterns. My roommate acquired other hardware and we had a pretty complete system with Lee Felsenstein's penny modem and video card, as well as an ASR 33 Teletype. I used this to do my linear algebra homework.I even had a couple of programs published in long gone computer magazines. I don't collect much (except dust), but I do still have the Cromemco Z2 I built and ThinkerToys 8" floppies. With a bit of work I'm sure I could get them to work. Thanks for posting!
That's really cool! I don't get a lot of first hand stories about the Altair. Did you guys have a sense of how historically unique what you were doing was, going from no truly personal computers just a few years earlier to that?
@@TechTimeTraveller Yes and no. No, we had no idea the Altair would be of historical import. My roommate sold it for an IMSAI as he wanted something more reliable. But yes, we know that this would change the world. BTW, I sent your video to my old buddy yesterday and replied that he has not thrown away anything from that time period. I know he his literal barns of stuff (including antique tractors that he repairs). He comes from a family of hoarders. I'm visiting him next week, but won't have a chance to tour his "collection". And don't remind his wife about all this.
I'll add that I was in the right place at the right time and met many of the principals, but did anything of consequence myself, although I had a perfectly fine career. I visit Xerox PARC before Steve Jobs did. But did I invent the Macintosh? ...No....
As far as I'm aware, the first home computer that was a available pre-built was the SCELBI-8H. Which, like the Mark 8, used an 8008. I suspect most were still sold as kits though. After the Altair 8800 came out, an improved SCELBI-8B was released, but it couldn't compete. I've built a SCELBI-8B repro, and I hope to build an Altair 8800 repro one of these days as well.
The SCELBI is the one machine I've never seen come up for sale anywhere. It'll be interesting to see what they go for if one does. Interestingly they helped keep some folks like the former owner of my Mark-8 using their machines via SCELBAL, their take on BASIC.
There was a lot of interesting stuff going on in New Mex back then. It gets overshadowed a lot by Silicon Valley but there was a really amazing nexus of talent there in the mid 70s.
Good memories… I bought an unused kit from an older gentleman in my rural Kansas hometown in exchange for yard and home chores in 1978. It was a fun and challenging project, and I loved being so close to how the technology worked. Later on I had a cassette tape rigged to boot the operating system once the boot code had been entered. Thought I was on my way to becoming Luke Skywalker!
As tech lovers, well speeking for myself anyway, I was 7 years old or so. The year was 1985, maybe 86. My mom worked for Burlington Coat Factory (it's called Burlington Stores now) - the original home store in Burlington, NJ. She was the payroll 'clerk' as was her 'title' back then. Basically she created spreadsheets but before there were GUI in big companies. Anyway, she came home one afternoon with this thing, it was a computer of sorts, 'portable' if you will, with a 5" CRT red screen (I'm pretty sure it was that small) and it was this janky contraption, whatever it was ridiculous, but she had work that needed to get done and it came home with her. That was the moment I realized all the taking apart my walkie-talkie radios and everything else in the house that had screws holding it together, that I was going to fall in love with computers. That things was 'work's' so I couldn't take it apart BUT maybe that Christmas or so we got our own actual real honest to goodness knock off IBM PC XT clone. Anyway, I didn't start out in the 70s with the original tech, and we had Dos 3.1 I think maybe 3.33 as my first OS, but man.. what a lifetime of learning and building and crying and spending crazy amounts of money on junk. Today I just have an AMD 5800x3d actual good pc I build a few years ago and upgraded recently. BUT, I spent my whole life playing with pc computers and know Microsoft products very well, I can fix ANYTHING, never had a computer beat me.. but this story was great, wonderfully done, I'm sad I missed the early first years, but I did get in early, just not this young. Thank you for the endless hours recording your recent journey with the Altair.
Hi. I bought my 8800 256 byte $395 kit the day the mag article came out. I have two basic paper tapes: MITS and Lawrence Livermore's basic and the 4K memory board. Assembled, tested, and it worked. Memory is vague but I had a rom boot loader. I used the toggles to load a boot strap "Jump loader: 303, address". I was very fast (fingers have slowed with age). I wrote a pre-pre-GPS geolocation program based on the 400 MHz timation satellite signal. I'm a Viet Nam vet, 6yrs Navy + 4yrs Navy reserve. The 8800 + nav solution was my senior undergrad engineering project. Yes I got an A. On to business. The 8800 has been unused ever since. It, the boards, basic tapes and a manual (hand pulled, no fancy motor driven) tape reader, the original magazine (I think I still have it) all sit on a library shelf collecting dust. If you want it all, lets talk. I think $100.00 would more than cover everything plus shipping costs. At this point I'd rather give it away than have a survivor throw it away. //jta//
Got the Altair kit when I was in college for electrical engineering. Mine worked first time, so I guess I was a better assembler than most. The static RAM card was originally supposed to be 256 bytes, but a note from MITS says they added the other 768 bytes (6 chips) for free as the cost of the chips had dropped. I had the machine for years and had added 3 more 4K cards to the mix. After college, I found other interesting machines (LSI-11, ...) and stopped using it. It went into storage until some time in the 90's when I decided to start playing with it again. Stupid me, I simply plugged it in and turned on the switch. Heard a loud BANG - one of the power supply caps blew. *sigh* I later needed some money and put it up on eBay - it sold for around $1400. I really wish I hadn't sold it.
My understanding is that the most important thing the Altair 8800 did was prove there was a real market for personal microcomputers. Once somebody makes money selling some new thing, there will soon be new, better things from other companies. Between The Woz looking at one and saying to himself, "I can make something better than that!" he did so, and Steve Jobs realized they could sell an improved version as a business. They incidentally convinced Commodore to do build their own, and Radio Shack was inspired to develop the TRS-80 as well. (For a while, the best selling micro was the TRS-80, because it was the only one with a chain of stores ready to sell it.)
I am the absolute worst person when it comes to math.. it was a real struggle to get it down. The key thing it seems is to understand is the opcodes the CPU uses to perform tasks and how to input the octal equivalents and how to structure things to make it work. I'm definitely going to spend some time learning machine language I think. Thank you for watching and your kind words. Much appreciated!
In 1988 my highschool was still teaching on ALtairs with Decwriter terminals. At home I was working with an Amiga and my old C64 and at school I was working on 15 inch greenbar paper.
My friend, you need to make animation shorts. That storm animation made me lol and I think it’s really the best kind of comedy. Because you don’t need context it’s just fun to watch the action. Those animations, the style you use and the humor, with the computer science nerdy charm. I think would do really well as shorts. I think you could cut a minute of them right out of the video.
Much appreciated, friend! I've thought about doing something like that, maybe not specific to tech, but a 1 minute video is literally 20 hours of work. I probably could get faster at it with more work. They're just so much bloody fun to do. :) Always wanted to be in a cartoon as a kid. Technology is wonderful sometimes!!
@@TechTimeTraveller When I was doing video work I found it got easier as i built a library of assets. If you think back to say, the Flintstones for example. Most of any one episode was reused assets. It’s just a matter of finding canned ways of doing it, and I understand it might seem like you’re giving away your best secret sauce here but I think it will pay off. I don’t see anyone else doing it. Anyhow, great stuff! Great way to start the week. 😊
@pikadroo Yes, I have been gradually organizing my assets (backgrounds, animations etc). Before I had them scattered about in the video project folders but now I'm trying to organize them. As time goes on I'm trying to learn to create more things and rely on canned green screen effects less. But it takes time to build up enough stuff and enough videos to be able to reuse it. Getting there!
I was an AT (technically AX, but that rate no longer exists) in the USN, and at BEE (Basic Electricity And Electronics - A School for electronics) around 1986, during our digital course, we learned about the Altair architecture (since it's fairly simple and easy to teach). Our final test for that was on actual hardware. We had to troubleshoot it basically by looking at how it decoded certain opcodes.
Oh the early days of home computing (my first was a timex sinclair I paid 150 dollars for and mail ordered from England). I worked with a guy who built his own computer (did all the soldering and placement of things on the motherboard..I'm still amazed as this was in the early 80's). I've heard about the Altair since the 70's and loved this video about it.
@5:36 that is something one sees a lot in stuff about old computers, about the lack of permanent storage and being at the mercy of the power supply, , it is like people these days think power was sporadically delivered in the before fore times and reliable power delivery is something that only recently came about.
Many former Altair hobbyists mentioned the risk of power loss, be it power Co or simply tripping a breaker. No one claimed it was an every day event but given there was no backup plan and how involved toggling anything significant on the front panel was..
I built an Altair 8800 in 1976. I ordered the kit as soon as I read the magazine article. I also bought the optional 4KB memory card kit. It got really old keying in that 20(?)-step boot program on the front panel so that the modem could pull in the Tiny BASIC from the cassette tape. I sold it and the SWTP TV Teletype in the early 1980s for a few hundred dollars as I recall. Of coarse, knowing what I know now, I should have kept it. Isn't that always the case?
Always the way. I tossed Tandy 1000s, the big grey Toshibas, even a Sun 3/80 (really regret that one.. those things have gotten super rare and went way up in price). It's just life I guess.. when it's something contemporary to us it doesn't seem special.
@@TechTimeTravellerLook at it this way - if nobody had thrown these out and everyone had saved them, they wouldn’t be as rare and wouldn’t be as valuable.
To flip some switches it takes a few moments, toggling 16 address switches, 8 data switches, one second a flip, so between 9 and 24 switches to flip, per programme byte it takes up to 24 seconds. Programming a real BASIC programming language into the MITS Altair 8800 it would take something like eight years to flip that in. For normal people . . . , The story goes that somebody programmed BASIC for the MITS Altair during his trip on board of an aeroplane. While he was flying to MITS because the sold them this BASIC. What is genius person that must be. This makes you humble when you think of that greatness.
It's not really accurate to say the switches are octal, not binary. They are certainly binary switches, they're just grouped in threes to facilitate using octal. It's not hard to use them in hex, if you prefer. Some people even used red and white switch covers to give them a visual reference for using hex, instead.
Yes correct. I was trying to explain the use of octal and the why of it but I probably stumbled a bit. What really did me in sometimes was getting confused with the decimal address numbers used in the manual example programs. Thank you for the clarification. This is why I'm glad (usually) that RUclips has the comment system. :)
Actual is just not compatible with electronics of the time. 7400 series chips would have 2,4,8 logic gates inside, not 3,6,9 etc. The IMSAI 8080 was a much more intuitive front panel
Thank you for explaining that it uses octal numbers - the grouping just didn't make any sense. It still doesn't, but now there's a story with it. That silkscreen never made any sense for the same reason.
In defense of octal, look at the instruction set. The right two octal numbers are often the registers without using an assembler, memorizing the instruction format can reduce the amount of referring to the instruction set each time you want to make changes to the execution. For the 8080, octal makes a lot of sense. Hex is more useful for text input or output as it uses a less tape for each byte. I admit, I like hex better as it is easier to deal with, number values. With octal one could make a simple instruction decoder to tape to the front panel for most of the common instructions, especially those that require one or two registers.
Some years ago I saw an Altair at an Antiques/flea market. It was in working condition and had a couple of extra boards that came with it. One was an extra memory board which didn't work. I was very tempted to buy it as I read the price tag as $400. Turns out I mis-read the price. The price tag said $4000.00! I had to walk away from it. Still, it was nice to have seen one in person.
It's kind of a double-edged sword with average folks knowing these are collectibles. It is helping save them from the trash, but at prices only deep pocketed folks can afford sometimes. Also can be frustrating when people think a dusty old c64 is worth $2k. I'm hoping prices will calm down. I've never actually met anyone in the forums or hobby that have paid $6700 for an Altair, so I'm left wondering who these folks are or of they're institutions etc. I've also wondered, seriously, about money laundering and stuff like that because I've seen these things sell and then pop up again and they have private bidder listings. You see stuff that shouldn't be 4 figures going for that kind of money. I mean probably it's collectors but it's weird they don't make appearances in the online vintage tech communities.
@@TechTimeTraveller hmm. Not quite money laundering, but I wonder if it's something of an extension of the old "buy a lot of art to avoid tax" deal... but applied to old computers? If so, it'd be a shame, because those only ever end up in warehouses rather than loved and appreciated. That said, $6k would be kind of chump change for those schemes - those usually deal more in $60-600k kind of ranges.
eh hehe. I remember my first computer and it too was an Altair 8800 and I was all of 14 years old. Assembly of an Altair 8800 requires a soldering pencil for almost everything. Don't worry b/c I also recently became a licensed Novice Amateur Radio Operator; the requirements included being proficient at sending and receiving Morse Code, electronics, theory, etc. I really got into that stuff and went deep so the Altair 8800 wasn't my first rodeo. It did take me well over a year to build however. To help I was a black hole. I absorbed vast amounts of help at all times. The Altair 8800 is baryonic insanity. Insanity congeals into fog banks and puddles around anything 8800. I knew absolutely nothing about computers and micro in 1978 but I learned fast, like a huge ocean wave catching a 90 pound super nerd, rolling and pummeling him onto the dry shore. If you've ever been 'shown the lights' by an ocean wave then you understand what I mean. And they did call this super nerd "Stud" or "Studly" for some reason. Wow, those were the days. I can't wait to watch this video and hope that it isn't disappointing.
The DEC PDP8 produced music the same way. Though with a 12 bit machine, it may have had better support for the in between tones and tempos. The point being, though, is that users of both machines found the same method and were in good company with each other.
Great video! The other interference you were hearing on your AM radio is likely caused by of the other modern electronics with which you are surrounded... microprocessors, switch mode power supplies, Ethernet networks, LED lights, ADSL/VDSL modems, etc. When the music program was written, the ONLY things in the home that generated radio interference were electric motors that had sparking commutators. AM (and shortwave) radio is virtually unusable in urban areas these days. Being an amateur radio operator I am well aware of the problems caused by the increasing RF noise floor in urban areas. Why do EV car makers want to stop putting AM radios in their cars?? Because it is almost impossible to make an EV (or any other modern car) that doesn't cause radio interference. Normal people don't care much about this issue, but maybe they will when their phones stop working due to some poorly designed electronics they have just purchased 🙂
Nunca lavas los pcb? Necesita detergente y cepillo, y una buena secada con calor seco sobre un crt o un mármol de una estufa, cuando acercas la imagen se pueden ver los hongos
I know people hated it in the 50s but when you look at it now it was really quite restrained in most aspects. Ford I think just oversold it; people thought they were getting a spaceship instead of a rehashed Ford. Apart from the Teletouch problems they seem to have been fairly reliable cars.
@@TechTimeTravellerThe Teletouch was a highlight. Watching a pack of bush jacketed beer and weed Albertans strip and rebuild the thing in a dirt floor shop was the best entertainment I'd had all year.
Martin Eberhard created an expanded version of the MITS 88-2SIO board and Mike Douglas has the FDC+ board. Both of those come with excellent documentation. You might want to send them an email to see if they are still available. I built an 8800c last year using those boards and a reproduction Altair CPU board. I put 4 3.5" floppy drives in a custom wooden chassis, set to 360 RPM to emulate 8" or 5-1/4"HD drives. and have it set up to boot CPM. I'd like to set it up one day to run a packet radio BBS.
Sorry for the long wait! This video took over 80 hours to produce, a good chunk of which was in the animated sketch at 40:12 . I'm particularly proud of the animated trees which are entirely my creation (the tornado is green screen.. not quite at that level of skill.. yet) - a simple thing to a professional animator but like summitting Mt. Everest for a novice like me. Okay, okay, a HUGE chunk of that production time was having to learn programming an Altair 8800 the hard way. The confusion of having dual purpose data/address entry switches and tiptoeing around octal took me down some seriously deep rabbit holes, and I am indebted to the very patient members of the vcfed.org forums for helping pull me out! Have I told you I suck at math? I suck at math.
An epiphany that hit while I was working on this and biting my nails over how long it was taking: I think I'm kind of done even trying to chase the algorithm. I'd rather not have the pressure of a schedule, so I can focus on making art. I really enjoy that last 10% of the process, when the main editing slog is done, and now I get to spice things up with a salty Robot TV director or get blown up turning on my Altair. Too often I've had to short circuit that to hit a self-imposed deadline, because, gasp, it's been 2 whole weeks since I last uploaded! I've done a lot of thinking and my preference is to just make the best quality video I can while still having a life outside of work (video editing most definitely is work, sometimes it feels pretty close to The Hot Place). If it takes 2 weeks to make a video at a sane pace, great, if it takes 6 weeks, so be it.
The channel recently hit 2 million views and I am absolutely blown away that my creations have been viewed that many times! Thanks to all of you for your support, be it just viewing, sending a positive comment, or joining my small but awesome Patreon crew. Hope you enjoy watching this video as much as I enjoyed making it! Cheers!
PS: Special thanks to my daughter Jacqueline for colorizing the Altair drawing from the MITS manual, as well as Steve Dompier's "Altair Music" sketch! I don't know if either ever existed in color but if they did I think she probably got pretty close to what they would have looked like!
No worries, brother. As usual, the wait was well worth it.
Well worth the wait for the video :) Merry Xmas and a happy new year to you.
The front panel alone is worth two grand, scuffs and all. A timeless classic.
The front panel switches are mapped in octal because that is the way the 8080's instructions are decoded. It makes it much easier to memorize all of the binary opcodes because you only need to learn a simple pattern, rather than all of the 256 possible codes. The upper two bits define the type of operation. The two lower 3 bit groups are the parameters specific to the type of operations.
Our early assembler was offsite on a timeshare machine. Programs came on paper tape. We had a paper tape loader in ROM. I did many program patches via a switch panel, as a reassembly was a laborious processs that involved punch cards and a trip downtown. It was handy to have the instruction set memorized.
Thanks for the video.
That's interesting - the explanation for Octal, that is.
What's even more interesting is that the Intel data books on the 8080, 8085, and the 8086/88 were all in hex, and every assembler I've ever used for these processors was in hex. You were not expected to memorize the specific field definitions for the op-codes, but simply know that something like 0x2ef8 was the opcode for "X", and the fact that 0x2ef9 was "X immediate" wasn't really relevant. At least in the contexts I was working within.
The only time I was concerned about bit-fields was when I was packing data for a specialized I/O chip or masking out flags in the status register.
Yes, the move instruction was based on 0x40, and the register or memory was based on 0x80. Then the registers were b, c, d, e, h, l m and a (0-7) (m was indirect (hl)). The ops were add, adc, sub, sbb, ana, xra, ora and cmp (0-7). Thus fully 1/2 of the 256 instructions were spoken for. If you look at a map of the instruction set, the middle is occupied with these instructions. And their layout makes sense in octal, 2 bits, 3 bits, and 3 bits. Intel was not trying to make the processor fit octal, it just happened to make sense.
The cpu had no multiply or divide instructions. We had no assemblers at first, and so memorized the instruction set by heart. I hand wrote listings and hand assembled them, writing the opcodes down from memory on the left side, then I would enter the program. We learned how multiply and divide worked by making routines that used bc, de, and hl to shift and add or subtract to make it work.
I think you can't imagine today what excitement there was at the time both building the machines from scratch and making them do what you wanted. I program complex routines in C and C++ and write drivers for Linux, but I learned %90 of programming back in those days.
I learned BASIC in Mr. Dyk's class in 1976 on 2 16K Altair 8800a micros, one with an ADM3 terminal and the other with a teletype 33. We also formed an after school computer club and made a computer dating service. The story on page 8 of MITS Computer Notes for July, 1977.
That's awesome! Thanks for sharing that
I feel so sorry for that teacher.
your school had computers in 1976 ? mine didn't even have one until the year 2000
@@belstar1128 yes, Mr. Dyk had the foresight to put his students on the leading edge of technology. Before then we used punched cards to send our FORTRAN programs to a computer across town.
It looks more like an amplifier equalizer than a controller lol I don’t know how you would even do inputs as it doesn’t have a keyboard either lol.
Thanks to the patreons for enabling this documentary excellent content
My first job was working in an Altair store. Since they only came as kits, I assembled them in order to sell complete computers. I also programmed them some. I always liked them and thought they were well built, but couldnt afford one (bought a TRS-80 instead, about 1/5 the cost).
But I figured over time the value would drop as they became obsolete and I could pick one up at a techie flea market (Dayton HamVention, for example) for not much. Never happened. They were expensive in 1976, never went down and they still are expensive today.
Yeah.. I kept passing on 8800s that were selling for less than $2k for years because I thought it was outrageous. And then suddenly it wasn't. I still wonder if my Altair's deficiencies were the reason for the low price, or if I just got extremely lucky because a bunch of potential bidders didn't want to fork over $6k just after Christmas and stood down.
Great video. Seeing your old Altar playing music was fun to watch. I have two IMSAI 8080's and two or three other S-100 buss based computers. My IMSAI's are a hodgepodge of cards inside, and the power supplies are over-designed linear tanks. I have them running two different operating systems. One is a custom OS design based on NorthStar DOS and the other is called ZRDOS, or Z-80 Replacement DOS (a Z-80 replacement for cp/m, which was designed for the 8080), custom BIOS, with the user interface of ZCPR3. Both systems use the Cromico ZPU. One of them runs both 8 and 5-1/4-inch floppies with a 20meg SCSI hard drive, and the requisite serial terminal. My second IMSAI is just a basic computer. Front panel programmed to boot. I think it's my favorite.
A friend of mine from college built his own S100 bus computer. He had a mix of boards from Altairs, Processor Tech, Imsai, and a few others. He had a slightly burned up front panel board from an Imsai, that needed a lot of repair. The board had bad chips, burned or missing traces, and a lot of bodge wires from repair attempts, He studied the schematics of both the Altair and Imsai panels, and then drew up his own simplified version. He replaced lots of triple and quadruple NAND, AND, NOR, and OR gates with diode wire OR arrays and inverters. In a few places he used discrete transistors. His Frankenstein panel worked as well as the Imsai one did, and he even added a few extra features.
He found a bunch of static 22 pin ram chips that would almost be a pin for pin drop in for the 22 pin drams MITS attempted to use on their DOA 4k ram board. He also modded a second MITs 4K dram board to use the refresh the drams using the Z80's refresh signals (after he replaced the 8080 cpu card with a "ZPU" card.) His power supply used surplus transformers and capacitors (totalling almost HALF a FARAD for the 8v line). The thing could have powered and ARC WELDER.
I worked at a small computer store in Manhattan while in college. The owner was literally a hippy, ex musician. I built SWTPC kits for customers that wanted them assembled. I also repaired bad memory boards that kit builders couldn't get to work. Most of the time the problem was a small short on the PCB where it hadn't been etched enough. I got pretty good finding faults with a cheap oscilloscope, logic probe, and a DMM.
I have sold the Altair 8800 on eBay for $10,000 - the record to date as of this post. I took a selfie with it for fun and posterity. I really appriciate the time and care you put into making this video.
Very cool. I was only 12 years old when I saw this on Popular Electronics and I wanted one so badly that I started learning electronics. By the time I was 15 I'd built an 8080a system that never fully worked - but the 2102 static RAM (1Kx1x8) board I build *did* work and I still have it. BTW: your production values are great and unique. Love this video and I'm subscribing and digging through your previous videos. Best wishes and Continued Success!
Many thanks for your kind words and thank you for subscribing! Did you build your 8080a system from wire wrap? That's awesome that you still have it!
@@TechTimeTraveller No, I soldered wires. It was kludgy. Here's the 1Kx8 Memory Card. It has eight 2102 (1K x 1bit) Static Ram chips. A labor of love.
agilefrontiers.com/assets/images/memory-1k.jpg
A computer that I ran into that predates the Altair by 2 years is the French made Micral-N which was manufactured back in 1973 and makes you think that the Altair 880 was modeled after it..
It also seems to have come out before the MCM which was WAY AHEAD of it's time !!!
Nice video. Watched the whole thing! The intro was pretty amusing and hooked me.
Using AM radios to play music is a trick that goes back a lot farther. I remember seeing PDP-8s doing it. It’s amazing the patience to come up with the right sequence of instructions to get the various tones.
Yes! I'd love to find a video of a PDP-8 or such doing it. As far as I know the Altair was first as a 'home computer', although who knows what experimentation people got up to with machines that came prior. I can't even imagine how Steve Dompier figured his music out! Way more patience than I have!
If we go back even further the TX-2 was the first via. a slightly different mechanism, but the concept of using a loop to produce a square-wave at a given frequency was well understood by the time of the Altair.
Great video. As a fellow artist i appreciate the creative touches and laughed out loud more than once. I needed those laughs today thank you!
Much obliged and glad my humor isn't too out there. :)
Stumbled on your channel by chance. I’m from U.K. and grew up with Sinclair computers in the 80’s great interesting video and well explained. I’m gonna subscribe and watch more of your content . Thanks Aron
Much obliged! Thank you for the compliment!
This is the first video of yours I've come across and as a hardware geek this has the be the most in depth look at an 8800 I have seen so far, most videos I have found just show a quick glance inside and then go off on the history of it. Cheers for sharing all the model and internal info all in one place!
Many thanks for the compliment!
Gosh! This is the inspiration I need to finish my Altair clone kit! Next year I should have enough time after work to actually do it!
thanks, I know a lot more about the altairs than I did before and was really entertaining to watch
I built an Altair 8800 in 1976, while still in High School.. I eventually got (2) 8” floppy drives for it, with a Tarbell controller, and got it to run CP/M.. next came a 600 baud modem, and CBBS software (dial up bulletin board system)… ah, memories. with all of that said, I’d recomend one of the $300 clones, such as the Altair Duino, has the front panel a simulates the 8080, its enough to run CP/M, Altair Basic etc.
As always love your sense of humor in your videos. It's awesome that you were able to obtain what's normally unobtainium. Here in the Philippines, it's even harder to look for vintage computers and ordering them from the US, Canada or Europe usually kills most of the budget with shipping costs.
Many thanks! I just saw a machine with a higher serial than mine sell for $6700 today (ulp). And yes shipping would be horribly expensive given how heavy they are!
it's hard to find anything vintage reasonably in thailand too. like even just 90s and early '00s era pc's. latter half of '00s and onwards you can just go to an it mall and pick up though.
Amazing, you brought up the Mark 8. My dad kitted it for the hobbyist market. Indeed, there was a user group called the Hal Singer User Group which was centered around the Mark 8. He was a part of that.
My father then went on to the Homebrew Computer Club where he was at the first meeting and worked with Apple back then.
That's awesome.. so by 'kitting', you mean he was providing it with additional parts beyond the board? My dream is to find some original copies of Hal's newsletters to have Grant Runyan's published words there. I know they're available online but something special about the original paper copies. I wonder if your Dad ever ran into Grant in their travels! Did your dad keep his Mark-8?
Years ago, I had one of the dual drive units. I think I paid $25 for it at a ham fest. There was nothing inside except for the power supply. I outfitted with a Morrow Wonderbuss, Intercontinental Micro s-100 single board, two 35 track dual side dual density drives, hooked up external 8" drives, external SASI 10mb drive, and used it as a development machine for years. Later, I stripped out the single s-100 board, and sold the MITS case for $250 to someone who wanted it as a collectible.
Darn! Yeah that's the story of many an upgrade. I curse myself for all the things I've tossed over the years. The Foley really seems to be super rare.. but I don't think I've seen on get near a Rev 0 value wise so still potentially attainable unless the market has changed.
I'm glad you mentioned Deramp I've been subbed to his channel for years now and he's why I have enough of on interest in the Altair as an actual computer to be seriously considering getting one at some point or building out a clone. I've nearly bought an 8800A more than once because they pop up working for so cheap because so many collectors don't want them for what ever reason. I've also considered just building a clone to get my Altair fix but it's around the same price as just picking up an 8800A but most the clones have the added advantage of being easily to swap into full S-100 bus machine if you want that.
Mike is a great guy, he has a natural talent for explaining tech. I've watched his Altair videos multiple times. His clone was really cool too.. I regret not buying one when they were for sale. And I agree I think the 8800a would be a great buy.. not as expensive as either the 8800 or 8800b, better power supply but still the essence of an Altair.
Yeah for me it's more about capturing the essence of the machine, it's also why I'm more willing to do stuff like PSU rebuilds on old machines than some folks are. It also helps I'm acutely aware of how easy it is for those old power supplies to blow and take out the machine with it and to me preserving the machine overall is more important that something relatively inconsequential as replacing the power supply especially when I know something like an 8800 I'll explore and use enough that the power supply failing is a serious concern.
Fabulous stuff, Brad! The time and effort you put into these videos really shows and is appreciated. The demonstration of the origins of computer music was really excellent - I'd read about it but now I've heard it! Wishing you and yours a great Christmas and new year!
Many thanks! I am trying hard to stick to a quality over quantity approach. It's hard sometimes because RUclips makes it competitive.. they're always guilting you with stats and showing you other youtubers in your niche who are rocketing past you. But I think the time taken here really paid off well and let me add things and fix more bugs. Thanks for the high compliment and glad you enjoyed it!
37:17 it looks like it wraps on overflow rather than saturates. That's good, it's what most processors do, some rely on it, for example if you keep adding 1 to a counter you usually want it to wrap around and keep counting rather than just stop counting
Fun fact: the same company also made an audio amplifier. I have one, and it has the same font on the faceplate that it is on Altair. It's not particularly good or bad, but it looks cool.
I didn't know that. I thought MITS stuck mostly to calculators and computer-like gadgets!
I can tell you what happened with the D7 bit being set by mistake on your addition program. The 8080 (much like the derivative z80) has a carry flag to facilitate doing 16 bit additions. In your case the carry flag would have been set and the rest of the addition goes on as expected.
Early micro computers were built to resemble mini computers like the PDP8 and PDP11 made by DEC. Since DEC used Octal notation, early micro computers followed that. The Intel 8080 instruction set actually did group bits into two 3 bit and one 2 bit combination when decoding the instructions, so it did make sense to describe the instruction set in octal. Later micro processors didn't follow this, the Motorola 6800 instruction set was listed in hexadecimal.
Much appreciated! I'm assuming it was the same and carried over from the 8008?
8080 and 6800 were both hexadecimal. i wrote code for both when they were new. 8080 was identical to z-80 code-wise best as i remember
@@jgunther3398 Intel's first documentation on the 8080 broke the instruction set up into octal digits when showing the encoding. Later instruction set listings were in hex. The z80 had a super set of the 8080 instructions. Mostly they used unimplemented 8080 opcodes as leadin bytes to change the operation of instructions. For example, one set of leadin bytes caused the instruction to use the IX or IY index register instead of the HL pair.
@@jgunther3398 The 8008 and 8080 opcodes are ordered in such a way that various bit combinations are in groups of 3. The basic MOV, LD, ADD, SUB, and similar instructions that specify a register can be represented in octal. This was obvious when you looked at the opcode charts with the binary groupings. However, Intel did list the entire opcode set in Hexadecimal. If you were programming the Altair from the front panel in "Machine Code", you might prefer to think of the bit patterns in Octal. However, if you were entering the code from an assembly listing, you might prefer to us Hexadecimal. Addresses made more sense to show in Hex rather than "split octal" The other reason that Octal was popular was that the DEC PDP-8 panel was in octal, and many programmers cut their eye teeth on a PDP8.
I always love coverage of the MCM-70 that ran a version of APL so it could get the most out of its extremely limited capabilities. It would have been differently interesting if it ran Forth, but APL actually had IBM backing. Computers could be so weird back then!
It is kind of a special machine. Wish I could find one!
I’ve only seen one at the Computer History Museum in Mountain View. I expect there are so few that they will all need to be handled institutionally. I think the best the public will get is some kind of emulator on BitSavers.
Killer Find, The Mixed bag means Notta!
I've yet to this day bring myself to spend the money on myself and build a new PC from the ground up. a Kid in the 80s & 90s, everything I had was Trash picked or Flea market cheap finds into my mish-mash WiteBoxes until I had something that would finally install Dos LOL
congrats on the new addition to your collection!
In a professional environment, I worked with two different S-100, Cromemco systems. The first was a Z80 computer designed for doing weather graphics. It was called a ColorGraphics LiveLine II. I think it used a Dazzler card, a DEC VT100 terminal, a 10MB hard drive, and a GTCO tablet. An 8-bit rudimentary graphics system used for broadcast meteorologists for their presentations. I couple of years later I was using a ColorGraphics ArtStar 3D Plus. It was a 24 bit true color system, but still based on an S-100 bus. The CPU was now a Moto 68020, and instead of CP/M, it ran a UNIX clone called CROMIX. Even with the 68000 based CPU, I saw references to Z80 in the files on the system. Oh yeah, this thing had a massive 200MB hard drive! I have some demo videos of the ArtStar, here on RUclips. It's what I learned 3D animation on, for better or worse. The ArtStar was also sold as a weather graphics system, called the LiveLine V. It even had a bit-slice processor!
I remember seeing the ad for this when I was in high school (I graduated in '75). I was dismayed at the price because it was well out of my reach. It was not clear to me what it could do that was actually useful.
I had previous computer experience. Our sixth-grade class helped beta-test the Plato Learning System on the Illiac at the university through terminals connected to the big machine across town.
It wasn't obvious that this could be connected to a terminal (and then there would be the additional cost for a terminal!). But I had been playing with binary numbers on my own for six years just because I figured it might be important, so the switches and lights on the front panel weren't completely alien to me.
I'm delighted to hear the music from your radio.
I remember seeing all the ads for the S-100 bus systems in Creative Computing. I didn't realize that bus originated with the Altair and I forgot that Microsoft basically got started selling BASIC (that they stole from Dartmouth) for the Altair.
Much fun! Thank you very much!
I look forward to your new videos so much, regardless of how long between uploads you need to get things to a point you’re happy with. Thanks for teaching me so much about these old machines!
I just pray I'm teaching the right things. :) I try to research as much as I can but the occasional booboo slips through.
You know what, though? I really like the looks of that Altair with the built-in 5.25" disk drives.
Such a wonderful video. I love the 8-bit references, specifically from Impossible Mission. I got some big laughs out of this. Thank you!
Thank you for the compliment. Means a lot!
@@TechTimeTraveller I grew up in the C64 era and these older-than-me machines fascinate me so much. Most of what you demonstrated was a little beyond me but made me glad I bought an Imsai 8080 replica to play with. Now, what to do exactly... 🤔
Awesome! Thanks for sharing your experience and the really interesting explanation!
This was my first computer - bought the kit in my teenage years. Loved it.
37:49 To explain this a little bit if you are curious. When you have an overflow it rolls over to 0 in the sense that 377 octal + 1 = 0. If you are adding more than that it continues past 0. You can think of it like an odometer rolling over in a car. Basically computers add binary digits from right to left. so basically it did add 2 + 3 to get 5 like you said. Then it went on to add all the 0 bits to get 0s. Then it added the last two 1s and got 10 binary. The 0 gets saved in D7 and the 1 ends up in the carry flag never to be heard from again. Overflows go off the end and whatever was the result of the lower bits is what is saved.
Thank you for explaining that so clearly!
That was awesome. So much to like about this video. You must have been over the moon when you got the audio happening, Media player today, Doom tomorrow
Thank you! I've always been into history and this hobby is one of a few things that can really transport you back, especially in my 1970s era house. The music sequence really brought the era to life for someone who missed it as a child.
The world's first home computer music was radio interference? Damn.
I guess I know where the FCC getting all militant about RF radiation in the late 1970s came from....
Fantastic video and great to learn about! :)
Thanks so much!
CAn only agree about the Christmas thing. I came into possession of a DEC digital Server with a Pentium Pro inside, just today. Because of a lowball "nah I am gonna be outbid anyway" offer I made on December 20th. got it for less than half the price that these machines usually command.
Oh my gosh, of course you're an Edsel guy. 🙄
I'm just kidding, all of the Edsel guys I know are decades older than me, but I love listing to them rattle on about old technology and mechanical stuffs. Still don't understand what they see in cars that look like that though. Awesome video, it was very much worth the effort!
Lol don't worry I ask myself that question every day now that I'm out. Obviously was too young when they were new. They're actually kinda restrained compared to other late 50s cars.. basically just Fords with a weird grille. I guess I like oddball/unloved stuff. And the Teletouch electric gear selection system. But it was one money draining hobby too many. Thanks so much for watching!!
Once upon a time, using the TRS-80 Model 3 and/or Model 4, there was a game (something about ghosts) that play wild and perfect music through a nearby AM radio. It was fully intentional, and done really really well. Probably till have these old computers kicking around in the basement. Maybe...
Quite a few years ago we visited a little one-man Computer Museum in Annapolis Royal, Nova Scotia. He had all sorts of amazingly early hardware, including the "first" PC, one of those from before the Altair. Had some super-early Apple hardware. All sorts of things.
Fantastic video! Thank you so much for sharing this!! ❤
Thank you for watching!!
I'm glad that you buy stuff like this and fiddle with it thoroughly so I don't have to spend the money to fiddle with it myself.
See people just don't appreciate the public service I provide here.. lol
Micro Instrumentation and Telemetry Systems (MITS) - Ed Roberts and Forrest Mims founded MITS in December 1969 to produce miniaturized telemetry modules for model rockets such as a roll rate sensor.
Fantastic stuff - you've earned a subscriber! I will openly admit that this era of computing doesn't interest me that much, just as I'm sure the 90s era I'm interested by doesn't appeal to others...
But, your presentation and passion for this is wonderful and this was a fun watch! I do love just how basic these machines are - there's something so satisfying about seeing PCB traces that were drawn by hand.
Many thanks!!
The only time I ever saw an Altair was in a locked, glass-fronted computer room in the old DeVry Institute of Technology Chicago location when they were focused on electronics degrees only. A few years back! Thanks for the memories.
Great opening!! So cool that you got one. If I'm ever "rich" I want to get one :) A while back I saw a Altair 680 on eBay for $4k. I had never heard of that one!!
One just sold today for $6700! And it had a higher serial than mine! Ulp!
Ah! Those were the days - when computers took up most of your desk and had flashing lights and switches..
Thanks for this riveting video and the trip to the past. Although I'm old enough to have used an Altair 8800, I haven't had this chance. The first computer I have put my hands on was the French-made MBC Alcyane, which was much inspired from the Altair to say the least. It wasn't a hobbyist machine though and not mine either, but belonged to a computer club. A big difference (and improvement IMO) is that switches were in groups of four, hence hexadecimal was being used 😁
Hearing music on the radio generated by the Altair was absolute awesome! Thank you!!
No problem. I'd like to thank @deramp5113 for introducing me to that via his own video. He had a proper portable radio and it sounds even better imo.
@@TechTimeTravellerOne reason it was so awesome, besides the work that originally went into figuring it out, but what you said... a radio probably was the 1st peripheral for the Altair and thus the 1st ever Personal Computer.
Love the colour coded wiring!
They literally bought the cheapest white wire they could find. :) It's like cotton candy in terms of texture and gauge.
4:58
That brings back a flood of memories. I couldn't afford one of these but I did build the Cosmac Elf in that time frame.
Too bad our house burned down about a week after I finished building it.
Worth the wait as always!
Many thanks!!
I love these blinkenlights boxes, thanks for coming up with these introductions. Because I can´t even afford a broken C64 I can at least by You gaze at this very interesting stuff.
And for an old stuff guy You not listening to radio anymore feels wrong. I love and still use fm radio all day, i grew up with radio, it was my window to the world (with all the different wave ranges)- I spent a lot of time in front of the dial as short and medium wave were still very propagated in the 70´s West Germany.
Anyway: a special thanks for that analog digital music, if I was living in the States I´d be itchy to come over and take a deeper look into different melodies and a better sounding recording. Maybe find the sending part and couple directly into it?
Have a beautiful Christmas, it is a nice blinkenlight bleep bloop box!
Where I live we only get a few stations.. mostly general listening stuff and I'm not a big fan of most current music. I was a huge radio listener when I lived near Toronto, so many great stations. But here our main station is a tourist serving outfit that plays the same songs over and over and over again until you hate them. So I've resorted to ipod or phone use. I do hear radio when driving with my wife now and then.
I did want to do more songs but it takes SO long to enter programs on the Altair front panel, and with old machines I get worried about stuff failing. The fan on my Altair isn't very effective and I have no idea how good the workmanship was on this PSU. But it didn't really give me any problems so maybe I'll be more adventurous. In my next video on it someday I'm hoping to connect to a teletype I have and try stuff like BASIC programming. Maybe I'll add new music too!
Have a great Christmas too! 🎄
Thanks for this detailed answer, I´ll stay tuned :)@@TechTimeTraveller
Thanks really enjoyed your video. Brought back fun memories of my work in the 70s and 80s fat fingering in a program on a mini computer. Starting the computer you would fat Finger in a program that would allow you to read a paper tape on a teletype and the paper tape would load in a program that could then read from magnetic tape that you could then install your operating system, etc..
The front panel is binary, it's just grouped as octal numbers. I don't get the need for all the references to octal. If the input were truly octal you would have 5, eight position switches. But you don't, it's just groups of 3 bits.
Yeah I didn't explain that real well. I suppose I should have said, the switches and lights are binary, but MITS grouped them to correspond with octal notation, which is easier than binary numbers for humans to work with/remember?
I have an Altair 8800a that has the same power supply setup as the original Altair but does have the thicker paddles. Fully working, nice machine.
Shortly after the Altair came out my college roommate assembled one. It was tough to get working (I remember something about him sitting in a dark room looking for a very pale trace on an oscilloscope). I was the software guy, much like you my first program adding 3 plus 4 to get 7. Later I wrote my own flashing light patterns. My roommate acquired other hardware and we had a pretty complete system with Lee Felsenstein's penny modem and video card, as well as an ASR 33 Teletype. I used this to do my linear algebra homework.I even had a couple of programs published in long gone computer magazines. I don't collect much (except dust), but I do still have the Cromemco Z2 I built and ThinkerToys 8" floppies. With a bit of work I'm sure I could get them to work. Thanks for posting!
That's really cool! I don't get a lot of first hand stories about the Altair. Did you guys have a sense of how historically unique what you were doing was, going from no truly personal computers just a few years earlier to that?
@@TechTimeTraveller Yes and no. No, we had no idea the Altair would be of historical import. My roommate sold it for an IMSAI as he wanted something more reliable. But yes, we know that this would change the world.
BTW, I sent your video to my old buddy yesterday and replied that he has not thrown away anything from that time period. I know he his literal barns of stuff (including antique tractors that he repairs). He comes from a family of hoarders. I'm visiting him next week, but won't have a chance to tour his "collection". And don't remind his wife about all this.
I'll add that I was in the right place at the right time and met many of the principals, but did anything of consequence myself, although I had a perfectly fine career. I visit Xerox PARC before Steve Jobs did. But did I invent the Macintosh? ...No....
As far as I'm aware, the first home computer that was a available pre-built was the SCELBI-8H. Which, like the Mark 8, used an 8008. I suspect most were still sold as kits though. After the Altair 8800 came out, an improved SCELBI-8B was released, but it couldn't compete.
I've built a SCELBI-8B repro, and I hope to build an Altair 8800 repro one of these days as well.
The SCELBI is the one machine I've never seen come up for sale anywhere. It'll be interesting to see what they go for if one does. Interestingly they helped keep some folks like the former owner of my Mark-8 using their machines via SCELBAL, their take on BASIC.
Being from New Mexico, I'm kind of proud of the machine, great video into the history of a great computer!
There was a lot of interesting stuff going on in New Mex back then. It gets overshadowed a lot by Silicon Valley but there was a really amazing nexus of talent there in the mid 70s.
DTACK Grounded was based in NM as well during the 80s. They introduced people to the Motorola 68000 CPU.
Good memories… I bought an unused kit from an older gentleman in my rural Kansas hometown in exchange for yard and home chores in 1978. It was a fun and challenging project, and I loved being so close to how the technology worked. Later on I had a cassette tape rigged to boot the operating system once the boot code had been entered. Thought I was on my way to becoming Luke Skywalker!
As tech lovers, well speeking for myself anyway, I was 7 years old or so. The year was 1985, maybe 86. My mom worked for Burlington Coat Factory (it's called Burlington Stores now) - the original home store in Burlington, NJ. She was the payroll 'clerk' as was her 'title' back then. Basically she created spreadsheets but before there were GUI in big companies. Anyway, she came home one afternoon with this thing, it was a computer of sorts, 'portable' if you will, with a 5" CRT red screen (I'm pretty sure it was that small) and it was this janky contraption, whatever it was ridiculous, but she had work that needed to get done and it came home with her. That was the moment I realized all the taking apart my walkie-talkie radios and everything else in the house that had screws holding it together, that I was going to fall in love with computers. That things was 'work's' so I couldn't take it apart BUT maybe that Christmas or so we got our own actual real honest to goodness knock off IBM PC XT clone. Anyway, I didn't start out in the 70s with the original tech, and we had Dos 3.1 I think maybe 3.33 as my first OS, but man.. what a lifetime of learning and building and crying and spending crazy amounts of money on junk. Today I just have an AMD 5800x3d actual good pc I build a few years ago and upgraded recently. BUT, I spent my whole life playing with pc computers and know Microsoft products very well, I can fix ANYTHING, never had a computer beat me.. but this story was great, wonderfully done, I'm sad I missed the early first years, but I did get in early, just not this young. Thank you for the endless hours recording your recent journey with the Altair.
Cool video! Happy Christmas!
Same to you!
Thanks, @@TechTimeTraveller!
Hi. I bought my 8800 256 byte $395 kit the day the mag article came out. I have two basic paper tapes: MITS and Lawrence Livermore's basic and the 4K memory board. Assembled, tested, and it worked. Memory is vague but I had a rom boot loader. I used the toggles to load a boot strap "Jump loader: 303, address". I was very fast (fingers have slowed with age). I wrote a pre-pre-GPS geolocation program based on the 400 MHz timation satellite signal. I'm a Viet Nam vet, 6yrs Navy + 4yrs Navy reserve. The 8800 + nav solution was my senior undergrad engineering project. Yes I got an A.
On to business. The 8800 has been unused ever since. It, the boards, basic tapes and a manual (hand pulled, no fancy motor driven) tape reader, the original magazine (I think I still have it) all sit on a library shelf collecting dust. If you want it all, lets talk. I think $100.00 would more than cover everything plus shipping costs. At this point I'd rather give it away than have a survivor throw it away. //jta//
Got the Altair kit when I was in college for electrical engineering. Mine worked first time, so I guess I was a better assembler than most. The static RAM card was originally supposed to be 256 bytes, but a note from MITS says they added the other 768 bytes (6 chips) for free as the cost of the chips had dropped. I had the machine for years and had added 3 more 4K cards to the mix. After college, I found other interesting machines (LSI-11, ...) and stopped using it.
It went into storage until some time in the 90's when I decided to start playing with it again. Stupid me, I simply plugged it in and turned on the switch. Heard a loud BANG - one of the power supply caps blew. *sigh* I later needed some money and put it up on eBay - it sold for around $1400.
I really wish I hadn't sold it.
My understanding is that the most important thing the Altair 8800 did was prove there was a real market for personal microcomputers. Once somebody makes money selling some new thing, there will soon be new, better things from other companies. Between The Woz looking at one and saying to himself, "I can make something better than that!" he did so, and Steve Jobs realized they could sell an improved version as a business. They incidentally convinced Commodore to do build their own, and Radio Shack was inspired to develop the TRS-80 as well. (For a while, the best selling micro was the TRS-80, because it was the only one with a chain of stores ready to sell it.)
Junior High, Summer School 1977, I watched a student in the computer lab do entries like you are doing, still makes no sense to me haha. Great Video.
I am the absolute worst person when it comes to math.. it was a real struggle to get it down. The key thing it seems is to understand is the opcodes the CPU uses to perform tasks and how to input the octal equivalents and how to structure things to make it work. I'm definitely going to spend some time learning machine language I think. Thank you for watching and your kind words. Much appreciated!
Computer molto interessante.complimenti al video,ottimo!
In 1988 my highschool was still teaching on ALtairs with Decwriter terminals. At home I was working with an Amiga and my old C64 and at school I was working on 15 inch greenbar paper.
My friend, you need to make animation shorts. That storm animation made me lol and I think it’s really the best kind of comedy. Because you don’t need context it’s just fun to watch the action.
Those animations, the style you use and the humor, with the computer science nerdy charm. I think would do really well as shorts. I think you could cut a minute of them right out of the video.
Much appreciated, friend! I've thought about doing something like that, maybe not specific to tech, but a 1 minute video is literally 20 hours of work. I probably could get faster at it with more work. They're just so much bloody fun to do. :) Always wanted to be in a cartoon as a kid. Technology is wonderful sometimes!!
@@TechTimeTraveller When I was doing video work I found it got easier as i built a library of assets. If you think back to say, the Flintstones for example. Most of any one episode was reused assets. It’s just a matter of finding canned ways of doing it, and I understand it might seem like you’re giving away your best secret sauce here but I think it will pay off. I don’t see anyone else doing it.
Anyhow, great stuff! Great way to start the week. 😊
@pikadroo Yes, I have been gradually organizing my assets (backgrounds, animations etc). Before I had them scattered about in the video project folders but now I'm trying to organize them. As time goes on I'm trying to learn to create more things and rely on canned green screen effects less. But it takes time to build up enough stuff and enough videos to be able to reuse it. Getting there!
I was an AT (technically AX, but that rate no longer exists) in the USN, and at BEE (Basic Electricity And Electronics - A School for electronics) around 1986, during our digital course, we learned about the Altair architecture (since it's fairly simple and easy to teach). Our final test for that was on actual hardware. We had to troubleshoot it basically by looking at how it decoded certain opcodes.
I have fond memories of toggling in programs in the 1980's, but I don't think I possess that patience anymore. Lol
It's fun for the first 10 bytes and then it's like.. are we there yet? Lol
If you saw the HP 9830 when it was new, the MCM-70's design makes perfect sense, and was actually a step above. :)
Bro how oldies use this blinking LED stuff?
Oh the early days of home computing (my first was a timex sinclair I paid 150 dollars for and mail ordered from England). I worked with a guy who built his own computer (did all the soldering and placement of things on the motherboard..I'm still amazed as this was in the early 80's). I've heard about the Altair since the 70's and loved this video about it.
Many thanks!
@5:36 that is something one sees a lot in stuff about old computers, about the lack of permanent storage and being at the mercy of the power supply, , it is like people these days think power was sporadically delivered in the before fore times and reliable power delivery is something that only recently came about.
Many former Altair hobbyists mentioned the risk of power loss, be it power Co or simply tripping a breaker. No one claimed it was an every day event but given there was no backup plan and how involved toggling anything significant on the front panel was..
Example program: is like entering machine language in a monitor but with switches. Amazing!
I built an Altair 8800 in 1976. I ordered the kit as soon as I read the magazine article. I also bought the optional 4KB memory card kit. It got really old keying in that 20(?)-step boot program on the front panel so that the modem could pull in the Tiny BASIC from the cassette tape. I sold it and the SWTP TV Teletype in the early 1980s for a few hundred dollars as I recall. Of coarse, knowing what I know now, I should have kept it. Isn't that always the case?
Always the way. I tossed Tandy 1000s, the big grey Toshibas, even a Sun 3/80 (really regret that one.. those things have gotten super rare and went way up in price). It's just life I guess.. when it's something contemporary to us it doesn't seem special.
@@TechTimeTravellerLook at it this way - if nobody had thrown these out and everyone had saved them, they wouldn’t be as rare and wouldn’t be as valuable.
Haha, I like how that little "safety first" robot looks like the ones from Impossible Mission!
To flip some switches it takes a few moments, toggling 16 address switches, 8 data switches, one second a flip, so between 9 and 24 switches to flip, per programme byte it takes up to 24 seconds. Programming a real BASIC programming language into the MITS Altair 8800 it would take something like eight years to flip that in.
For normal people . . . ,
The story goes that somebody programmed BASIC for the MITS Altair during his trip on board of an aeroplane. While he was flying to MITS because the sold them this BASIC. What is genius person that must be. This makes you humble when you think of that greatness.
It's not really accurate to say the switches are octal, not binary. They are certainly binary switches, they're just grouped in threes to facilitate using octal. It's not hard to use them in hex, if you prefer. Some people even used red and white switch covers to give them a visual reference for using hex, instead.
Yes correct. I was trying to explain the use of octal and the why of it but I probably stumbled a bit. What really did me in sometimes was getting confused with the decimal address numbers used in the manual example programs. Thank you for the clarification. This is why I'm glad (usually) that RUclips has the comment system. :)
Actual is just not compatible with electronics of the time. 7400 series chips would have 2,4,8 logic gates inside, not 3,6,9 etc.
The IMSAI 8080 was a much more intuitive front panel
Thank you for explaining that it uses octal numbers - the grouping just didn't make any sense. It still doesn't, but now there's a story with it. That silkscreen never made any sense for the same reason.
In defense of octal, look at the instruction set. The right two octal numbers are often the registers without using an assembler, memorizing the instruction format can reduce the amount of referring to the instruction set each time you want to make changes to the execution. For the 8080, octal makes a lot of sense. Hex is more useful for text input or output as it uses a less tape for each byte. I admit, I like hex better as it is easier to deal with, number values. With octal one could make a simple instruction decoder to tape to the front panel for most of the common instructions, especially those that require one or two registers.
Some years ago I saw an Altair at an Antiques/flea market. It was in working condition and had a couple of extra boards that came with it. One was an extra memory board which didn't work. I was very tempted to buy it as I read the price tag as $400. Turns out I mis-read the price. The price tag said $4000.00! I had to walk away from it. Still, it was nice to have seen one in person.
It's kind of a double-edged sword with average folks knowing these are collectibles. It is helping save them from the trash, but at prices only deep pocketed folks can afford sometimes. Also can be frustrating when people think a dusty old c64 is worth $2k. I'm hoping prices will calm down. I've never actually met anyone in the forums or hobby that have paid $6700 for an Altair, so I'm left wondering who these folks are or of they're institutions etc. I've also wondered, seriously, about money laundering and stuff like that because I've seen these things sell and then pop up again and they have private bidder listings. You see stuff that shouldn't be 4 figures going for that kind of money. I mean probably it's collectors but it's weird they don't make appearances in the online vintage tech communities.
@@TechTimeTraveller hmm. Not quite money laundering, but I wonder if it's something of an extension of the old "buy a lot of art to avoid tax" deal... but applied to old computers? If so, it'd be a shame, because those only ever end up in warehouses rather than loved and appreciated. That said, $6k would be kind of chump change for those schemes - those usually deal more in $60-600k kind of ranges.
eh hehe.
I remember my first computer and it too was an Altair 8800 and I was all of 14 years old. Assembly of an Altair 8800 requires a soldering pencil for almost everything. Don't worry b/c I also recently became a licensed Novice Amateur Radio Operator; the requirements included being proficient at sending and receiving Morse Code, electronics, theory, etc. I really got into that stuff and went deep so the Altair 8800 wasn't my first rodeo. It did take me well over a year to build however. To help I was a black hole. I absorbed vast amounts of help at all times.
The Altair 8800 is baryonic insanity. Insanity congeals into fog banks and puddles around anything 8800. I knew absolutely nothing about computers and micro in 1978 but I learned fast, like a huge ocean wave catching a 90 pound super nerd, rolling and pummeling him onto the dry shore. If you've ever been 'shown the lights' by an ocean wave then you understand what I mean. And they did call this super nerd "Stud" or "Studly" for some reason. Wow, those were the days.
I can't wait to watch this video and hope that it isn't disappointing.
interesting video never seen a Altair running and i never knew you could could make music on it lol.
I was born in '85 and I've always been into computers since I was 10. It's always wild when I see "ancient"computers like this haha
The DEC PDP8 produced music the same way. Though with a 12 bit machine, it may have had better support for the in between tones and tempos. The point being, though, is that users of both machines found the same method and were in good company with each other.
Alright!!! It’s out! Thanks for the entertaining edification.
Thank *you* and hope you enjoy!
Pretty cool, thanks for sharing.
Great video! The other interference you were hearing on your AM radio is likely caused by of the other modern electronics with which you are surrounded... microprocessors, switch mode power supplies, Ethernet networks, LED lights, ADSL/VDSL modems, etc. When the music program was written, the ONLY things in the home that generated radio interference were electric motors that had sparking commutators. AM (and shortwave) radio is virtually unusable in urban areas these days.
Being an amateur radio operator I am well aware of the problems caused by the increasing RF noise floor in urban areas. Why do EV car makers want to stop putting AM radios in their cars?? Because it is almost impossible to make an EV (or any other modern car) that doesn't cause radio interference. Normal people don't care much about this issue, but maybe they will when their phones stop working due to some poorly designed electronics they have just purchased 🙂
Wow, you needed to have your RAM in pairs back in those machines just like we do now; interesting. I guess some things really die hard!
Nunca lavas los pcb? Necesita detergente y cepillo, y una buena secada con calor seco sobre un crt o un mármol de una estufa, cuando acercas la imagen se pueden ver los hongos
My first computer experience was with my friends IMSAI-8080. I did a lot of soldering back then ;-)
Yeah, that radio-tone thing is just like a guy on another video showed us a pro minicomputer or bigger/older mainframe doing.
On the Edsel side quest, Cold War Motors here on RUclips did resto-run of one last year I think? What a neat car. A lot of intricacies.
I know people hated it in the 50s but when you look at it now it was really quite restrained in most aspects. Ford I think just oversold it; people thought they were getting a spaceship instead of a rehashed Ford. Apart from the Teletouch problems they seem to have been fairly reliable cars.
@@TechTimeTravellerThe Teletouch was a highlight. Watching a pack of bush jacketed beer and weed Albertans strip and rebuild the thing in a dirt floor shop was the best entertainment I'd had all year.
Martin Eberhard created an expanded version of the MITS 88-2SIO board and Mike Douglas has the FDC+ board. Both of those come with excellent documentation. You might want to send them an email to see if they are still available. I built an 8800c last year using those boards and a reproduction Altair CPU board. I put 4 3.5" floppy drives in a custom wooden chassis, set to 360 RPM to emulate 8" or 5-1/4"HD drives. and have it set up to boot CPM. I'd like to set it up one day to run a packet radio BBS.
I think if I want to get into teletype use that'll have to be the way. The SIOB boards are crazy rare and expensive.