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- Опубликовано: 11 дек 2016
- What's inside the world's first portable microcomputer?
The Osborne 1 from Osborne Computer Corporation torn down.
An Adam Osborne and Lee Felsenstein design.
ROM Dumps:
www.eevblog.com/files/Osborne1...
www.eevblog.com/files/Osborne1...
Field Service Manual:
maben.homeip.net/static/S100/o...
Technical Manual: history-computer.com/Library/O...
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Looks like he saw a portable Singer sewing machine case and said "Let's put a computer in there".
That was my thought the whole time. I almost wondered if maybe they got a good deal on some sewing machine cases, and built it to fit -- who cares about wasted space, we got the case for $1!
It was often referred to as a "sewing machine portable computer".
Groundbreaking indeed... if you dropped it, it'd break the ground alright
All the extra space in the cover / keyboard would make it a smuggler's dream :)
Wow! I had one of these as a kid. My mom used it in grad school, and then when she switched to a PC I got her O1. I used the external video! I think a lot of people used the external monitor. In the business school my mom studied in, it was common to have an external display in the office, but you could take the computer home if you needed to work on a paper or something.
Dave, I was just beginning my first company when this came out. It WAS exciting for many people! I can't believe I rushed out and bought one as soon as they were available. I used it for a while to do all the things that needed doing back then for a new little company, that would have been called a "cottage industry startup ". It was a great time to be able to start a company with virtually no capital and just an idea of what to do with the thing to get it going. Well, I guess I ought to tell you what I know about some of the questions here.
One thing which seems to be on everyone's mind is: why is the case so BIG? Why is the keyboard case SO HUGE with SO much wasted space inside? Why is there so much wasted space here, there and everywhere? Well, the answer is very funny! It seems that osborne came across a warehouse full of empty cases for sewing machines at a bargain price, so they became the cases for the first run of the Osborne luggable computer! There is such an odd mechanical design and layout because all the pieces had to be put into the sewing machine case! The case was not designed for the computer, which would have made it much sleeker and streamlined. The computer had to be designed to fit into the case! Actually, I think that is quite clever. There was no standard or other designs to use as examples of how the design ought to look. It was just made so bulky because it was cheap and already made! Osborne did not have millions to spend designing the world's sexiest computer, and as you said, they did not know how many they would sell. Coming across all those empty cases they could just buy and insert a computer into fit their needs perfectly!
One thing that I read about Osborne, which I have never verified, was that Osborne didn't have a typical cost control system/authorization process for controlling how purchases were made and how costs were controlled. If you wanted a new exotic office desk and chair, like the guy down the hall got, you could simply buy one, and charge it to Osborne's account. I can imagine how such policies would bankrupt a new, small business very quickly.
I was very surprised when I read that Osborne was going under, after such a stellar startup! But, when I read v about the way they conducted their business, it was not hard to conclude that they could not survive. Thanks for presenting this tear-down!
The next version, the Osborne Vixen was pretty much the same form factor.
25:28 Dave, I might be wrong but that sensor could be looking for the write-protect notch to see if it had a sticker covering it or not.
Correct.
That second sensor on the floppy is the write protect notch, not disk presence.
Yes. The only way to know if a disk was there was to spin it up and look for index holes.
The sensor near the middle is the spinning sensor. The sensor on the left was not a spinning sensor. It was on the edge away from the circular disk.
25:06 - disk start of sector sensor
25:28 - disk write protect sensor
I am too familiar with that write protect sensor. To use the other side of the disk, we used a hole punch to make a whole on the opposite side of the disk. Sometimes we used scissors to square up the hole. After we punched the holes, we could cover them up with special labels to write protect the disks. We even used masking tape to write protect the disks and block the light on that far left sensor.
I had a purpose-made square hole punch for that back in the day. :D
+Bakamoichigei I made removable write protect covers from a piece of dark colored paper that would cover the notch while sticking out the front of the drive for easy removal / insertion as needed.
Wow! I remember using one of these as a student in 1983 while being on work placement at the then Royal Aircraft Establishment Farnborough. I had joined a team of boffins who were working on helicopter gearing noise. To keep me busy and stop me from interfering with the real work, I was consigned to a very small room, the tea room as I remember and asked to write a basic fast Fourier transform simulation program with a high pass filter to identify the lower gear frequencies and exclude the higher pitch noise in the cabin. I don’t think they used my program. I do remember it creating an overwhelming amount of data.
The IBM 5100 was the first computer I got to spend serious time with. It is an earlier portable as was noted previously.
At 25:30, that optical sensor is for write protect. There is no sensor for disk insertion.
In the late 80's, I learned CP/M on this incredible machine... long time a go and nice to see it again - thanx!
The Osborne was the first _successful_ portable computer, but it was not the first "portable" computer. That would be the IBM 5100 from 1975, which they proudly advertised as a "Portable Computer" despite the fact that it weighs 50 pounds!
But one of those would be essential right before 2038
John Titor collects them
After the IBM 5100 comes the HP-85, and then the Osbone 1
True fact.
The 50/60 markings on the spindle of the floppy drive don't indicate the rotational speed (it would have been a couple hundred RPM), but what set of markings to look at depending on if you were using a 50 or 60 Hz strobe light to calibrate the speed.
themaritimeman Makes sense - thanks!
themaritimeman You could use fluorescent lights as the strobes - two freqs make it global...
Just like a turntable.
Todd Berg
Yep! But only with older fluorescent light fixtures that use magnetic ballasts. :P
Exactly. Dave's motto seems to be "If you're going to be wrong, do it at the top of voice".
i have one of these in my closet. still works. has all the fancy addons, and twice it's weight in software manuals with it. my grandfather used it when he designed satellites at ford aerospace/loral
Outstanding!
17:22 Oh! LOL Brazilian viewer here! haha nice to see that!
Brazilian IC in the 80"s, that is new to me!
Very cool indeed! But apparantely they no longer manufacture in Brazil.
Yea, from the 70's to the 80's, during the military government, some IC factories were been here, as many other big industries. We were living which was called the "economical miracle" but the truth was that we have just expended much more than we had, and they hided it from us... Well, and now it happened again, but that time we have no "Big factories" and no great constructions, no good hospitals or schools or universities...
+H3000 Yes, we dont have the base tecnology to develop and assembly it here.
Estranho discutir o Brasil em inglês... Hahahahahahahahah
Fantastic breakdown, review, and history lesson. Love your stuff!
I remember playing with my dads one of these. I was 8 in 81
I seem to remember it being quite yellow then.
Your Osbourne 1 has an 80-column video upgrade installed. From the Wikipedia page:
The Osborne corporation offered a "Screen Pac" 80-column upgrade that could be switched between original 52 column and 80 column modes. Osborne 1 systems with the 80-column upgrade have an RCA jack installed on the front panel to allow users to connect an external composite video monitor. This modification was developed in Australia by Geoff Cohen and Stuart Ritchie and taken to the US by Stuart who turned up unannounced and sat outside Adam Osborne's office for two days. Osborne bought the mod as soon as they saw it and both of them worked with the Company to implement the mod. As a nod toward where it came from it was called the "Koala Project". Geoff went on to invent many other upgrades for Osborne's and was regarded as the Australian expert on the computers.
That explains the bodge wires. The daughterboard sits between the CPU and video connectors, but that still doesn't give it all the signals it needs so you have to tap various places on the logic board.
Hi, I enjoy your teardowns. I just wanted to point out one thing, when I was working on pc's, xt's, and at's we frequently had to adjust the speed of the floppy rotational speed by removing the drive from the drive case, and use the ever present fluorescent light as a 60 hz source and tweak a 10 turn trim pot. The drives were inclosed in a heavy cage that was gold anodised. If you were lucky you could sneak your jeweler's screwdriver in between the holes in the cage and save yourself the trouble of having to remove the drive and then reinsert after the adjustment. h what memories.
I think the Gerry rigged parts are always the best part of these teardowns.
How did I miss this video! You saved me a bit of time and trouble with your teardown. I have an Osborne 1 and the follow up model the "Executive" OCC 1 and OCC 2 respectively.
I actually used these back in the day but neither machine has been powered up in decades. I belive I still have a full set of software someplace as well. These were amazing machines in their day but I definitely do not miss Wordstar! My two machines will be going to a new home with a nearby computer museum that only has a Model 1, in fact I think their website stated that they had never even seen an Executive! Better for lots of folks to see them than have them sitting in a closet for another 30yrs.
first computer I worked with was Corvet (I think it was Russian made) in 1994. That was awesome time. you are interacting with the new technology and work/actually write programs in Basic language. you took me back to that time, Dave. 😊
The video board is an Australian add on to give 80 x 25 display on an external display using the composite video connector. It was installed here in Australia. It was accepted by Adam Osborne and here we honoured warranty with the changes made. Interestingly the Osborne 1 sold here in Australia for $1795 where most other importers of computer marked it up 200% - 300%.
I had forgotten about that mod as I never saw one.
Brazillian here, never knew we had a TI fab in the 80s... we sorta have only one national fab today, but they do custom chips that are not really for personal computers...
We have more than one actually, but yea, they only do custom chips. From 70's to 80's we had some big TI factories, with good technology for the time.
Raimar Lunardi we do have an IBM factory, but last time i checked it was still not done and it would only do 45nm chips, which is 2010 technology.
and then there is the factory you mentioned, which does... RFID tags for livestock.
That's right. Brazil has a silicon factory just to track bulls in farms. Bus cards maybe, but mostly just the bulls.
Interesting. I thought there were no silicon factories left here...
I believe that the "floppy detector sensor" was actually the "write protect sensor", at least fom it's positioning, if the sensor was "blocked" the disk couldn't be written too, otherwise it could. We use to use hole punches to make "flippies", a sort of double sided floppy that had to be flipped over too use the other side (on single sided drives) or to make obsolete software floppies into data/writable disks
Great Video - I never realized it was so short - Also I'd always though there was other circuitry in the Keyboard case - Strange its so big . . .
Fun tear-down, thanks!
The second optical sensor on the drive was the write-protect, not disk presence.
Now you get keyboards the size of that screen and screens the size of that keyboard
Absolutely love the vintage PC teardowns
10:34 The "wasted space" is to protect the electronics board from impact damage. It will be lugged under an airline seat after all..
keyboard would have been popular with smugglers
I almost picked one of these up once, when it was on the $1 table at the local computer surplus store. They had two of them, both in very good working order, and neither of them showed any yellowing of the case. I believe most of the people who had these used them for field diagnostic work, if they weren't using them as business computers.
Nice review. Ozzy 1 was my first computer. I typed my dissertation on an Osbourne One. I printed it out using an Electric Typewriter with a home brew serial adapter with about a two characters a second output rate. It would take around ten hours to type out the entire dissertation. Each page had to be fed into the typewriter manually of course. My next "PC" was a Kaypro when I couldn't find an Osbourne Executive to buy.
@3:04 keeping all the nerds under control :) He deserves a medal. Little Stevie Jobs and his mate Woz always talking up at the back of the meeting
Dave, don't give me flack for giving you a thumbs up after just 55 seconds. I mean, it's EEVblog, it's a vintage computer, it's bound to be a great video! Thanks as always for giving time to vintage gear.
I love that the blue bodge wire at 18:15 is held down by the resistor. Resistor must have been inserted after the free flowing wires.
On second thoughts, they probably just jammed the wire in the empty space after resistor installation...
No real-time clock, every file date was 1-1-80. :)
CP/M didn´t use file dates....when i remember correctly.....
@@tubical71 True, CP/M computers had no concept of time and date.
The spaces in the front are expantions bay in a way. One for the modem and one for the battery.
The power supply is a pretty standard one, used for many projects. The strobe disc is for 50 and 60 Hz power line frequency. Double sided floppies were hard to make due to fragility of the head assembly. A double sided one impacts TWO head assemblies across the disk surface. The "big power resistor of the CRT is a high value (multi megohm) bleeder resistor.
The more portable computer was the Radio Shack/Tandy model 100 that ran from 4 AA batteries.
I remember one of my teachers at college calling in the computer lab with one of these. Everyone was like WOW a portable computer. We had to make do with a research Machines 380Z back then. Ah the nostalgia.
I love that cable that goes under the resistor :-)
The other sensor is for detecting the write-protect tab, not disc presence
A nice teardown. One has to remember that all PCB design was by hand and double sided tech was difficult to work with as you had to use transparent sheets and use overlays to see where the routing was available. Putting another socket would have meant a complete reroute and be expensive in terms of time costs. With the benefit of hindsight and modern technology it is easy to criticise what was then highly complex work, requiring skills that were hard earned and now forgotten in favour of pressing a button. I designed PCB's for a variety of kit for the BBC in that era and would have loved the current freeware apps and computing power!
love love love the old PC teardowns! On the floppy drive at 25:28 I think that's a write protect sensor? Cheers from snowy Canada.
Brazilian viewer here... we had two fabs in my area alone (RCA and SID) but they are long dead now...
Love these vintage computer teardowns.
my dad still has his, serial number A06198 still works like a charm complete with bootdisk and all :) bought it brand new back in the day! there is a few problems with the keyboards if they've been left sitting for a while... generally upright in it's "briefcase" position where the weight is pushing onto the keyboard... did have to open it up and clean a few contacts and wiggle the pieces of laminate apart to get the keyboard working again(i've seen a few modded ones or replacement keyboards for them) but it's a solid machine! our has the 4k modem built into it though and the pigtail cord on the keyboard!
Worked on a few of those in the day. They actually had a portable power setup, I bought a pallet full at one of the auctions. It was one of those shoulder-strapped portable TV lead-acid packs, 12V at about 8AH or so. It didn't use that front plug, tho. There was a small (about 2" sq by 4" long) aluminum box with a cig lighter 12V plug hanging out of one end, and a female IEC out the other. Clever box. Had two transistors and a pot core transformer as a free-running hi-freq inverter. They rectified the output and fed slightly filtered DC into the AC input of that Astec P/S. About 250VDC IIRC. Power supply ran happily on DC. The little box was even cool running. The o-1's PS was a 35w unit so you could squeak an hour or 2 out of that battery. I would rewind those little units to get 30VDC+/- to run a car amp with some headroom. One would do about 60W and could run an Osborne Exec barely.. The exec had a 65W astec. I bought several of both P/Ss, as the radio Shack TRS-80 model III/4 could use the 35W as a drop in. And adding floppies to the base model required a second 35W. Model 4 used the 65w directly, IIRC. Sold a lot of those mods in the early 80's. Fun times.
Wow, I had one of these back in 82-83, probably the only electronics device that I never took apart. Maybe because it cost more than my car.
I didn't have it long, it was so hard to use with all the disk switching, with some CP/M programs it just didn't have enough space.
My first database was on an Osborne, personal pearl... that's going back in time.
Thanks Dave!
I'm sure Dave knows this and just misspoke, but at 24:08, it's 50/60 hz strobe, not 50/60 RPM - if you had fluorescent lighting, it was stroby enough to calibrate the speed. Incandescents gave a blurry, barely there effect.
boy that brings back memories, I designed PC boards from 1779 to 1982 in Silicon Valley mostly for defense contracts, everything was done by hand, applying tape for traces. We couldn't run traces under IC's and through hole were frond apron, it involved hours of mental stratration
Frustration. What a pain in the ass it was. Dave
A board that size would take weeks to design. Usually the electrical engineer layer out the location of individual component then I would have to figure were to lay traces. We usually got the final design after two or three prototype runs, two or three board made. Dave
If I remember correctly we laid the board out at twice the size then reduced it to make the negatives for the PC board manufacturer that was outsourced. Silicon Valley at that time saw incredible place. Dave
A true pioneer, PC boards before steam engines!
This video tickles my fancy, the Osborne 1 was the first computer I ever owned!
There was a 300 baud modem available for it. The previous owner of mine had sprung for this extra. The modem slid into the diskette storage slot under the left drive and plugged right into the modem port with a very short cable. The UART behind that 25-pin serial port was only capable of (I think) 1200 baud maximum, and I was never able to get my hands on a 1200 baud modem while I had this machine, so I settled for the 300 bps. I tried a few different more modern 2400 and 9600 bps modems, but it wouldn't even talk to them.
I used a Commodore 1702 monitor with mine for a while, but quite honestly that little bitty CRT was quite clear and wasn't fatiguing to stare at for hours on end, so I mostly didn't bother.
The only video games it had were the ones I typed in BASIC from the back page of National Geographic Kids magazine.
In Feb 1982, I had to decide between Apple 2c (4800USD), IBM PC(5300USD) and Osborne1 (1795USD) which included software, Osborne 1 won. I still have it and all its original software. Just needs disk drive belts. It was the longest lasting PC I've had. Thank you for this post!!
bellissimo video, complimenti!! ^_^
Looks more like an old oscilloscope
Dave, it is my idea ,the audio has a background noise?
The camera with shotgun was further back than normal to get the wider shot.
The image really looks better in this way.
Rumor has it that the 5" CRT was from a an oscilloscope. Osborne got them cheap.
wow......
I lugged around the first Macintosh portable! What a beast and, wow, I sure felt cool in the airport!
Sensor at 25:30 is to sense if the write-protect tab on the floppy is in place or open to allow writing.
Dave, I think the second sensor in the floppy drive (25:30) is actually for the disk write protect tab.
The presence of a disk is all taken care of via the huge mechanical lever and hub clamp mechanism. Probably a microswitch.
The Z80 on a daughter board board screams of "feature creep". I wouldn't be surprised if the Z80 and a couple of the other chips could be removed from the daughter board and placed in the sockets on the mainboard, and "almost" work. It just looks like they needed some pretty fundamental changes a bit late in the design...
I can almost hear the designer cursing under his breath as a late requirement arrives on his desk after he'd already finished all the board design (probably by hand), closely followed by "oh sod it, daughter board!".
I hope you find a CPM disk, just a word of warning from the world of old computers, those 4116 DRAM can be a world of pain. They require 3 power rails, so a fault in any of those can cause all kinds of issues (or death), and I can't help noticing they're not socketed.
Still amused by the track lengths with RAM and CPU on different boards! Little to no worries about propagation delays. They were simpler times, that's for sure!
I really like old computers. I am currently making a copy of the Altair 8800 by duplicating the pcb's. The board layouts really show how much more difficult it was to create boards back then but I am making the copies as close to the originals as I can despite complaints from my pcb cad DRC.
^.... take it apart !!!! Thank you dave. Made my day !
You could give it a RetroBright treatment. I'm sure it would look cool in its original color.
My best guess for the oversized keyboard is in case someone dropped it on its face. Crumple zone.
I had one of those along with an OKIDATA dot matrix printer. I used to insert the wordstar disk in the A drive to write the program, pull it out, and insert the Dbase II disk to run the program. Data was on the B drive floppy disk.
I think that 2nd photo sensor on the floppy drive was for write protect notch detection not for disk presence. Before those nice little plastic sliders on 3-1/2" disks there were hand-held disk notchers and round plastic and paper stickers for write protect on 5-1/4" disks.
Nice teardown!
You should replace those Rifa brand paper dielectric EMI filter caps on the Astec power supply with modern safety-rated poly film caps. The old paper dielectric caps notoriously burst into flames under power after 30 years or so. One of them in your computer has already blown.
The most common problem I've personally encountered in those old floppy drives is the grease drying out in the spindle and hub clamp bearings. I've been able to work oil into them to get them spinning freely so far. The hub clamp is usually not too hard to disassemble, while the spindle might be harder to get into. The second optical sensor would be the write protect notch sensor.
Remember the flippy discs? You could use both sides by flipping it over (had two write-permit notches.) I used to have a notch cutter that turned SS into DS. Had a bunch of write protect tabs that made great EPROM window covers!
This machine reminds me of the Commodore SX-64, which was the same type of deal as this one, but with a C-64 inside (and only 1 floppy drive). I think it was from 84 or so, and I remember playing with it as a little kid.
That second sensor in the floppy drive looks like it was the write protect notch sensor.
Thank you for the teardown. The first computer I ever worked on was the KayPro II luggable CP/M computer. I cut my teeth per se on hardware support.
Show us the switches in the keyboard!
I wonder if it’s beamspring
Andrew Joy it's a foil on foam mechanism as I recall. It's been nearly 30 years since I opened one up, so I don't remember for sure. The Kaypro (an Osbourne competitor that I spent a lot more time screwing with) was definitely foil on foam.
It wont be a beamspring, they where exclusive to IBM, and fucking awesome ! I have one converted to USB.
Foam and foil is a bit disappointing , i was hoping for something a bit better like older cherry or alps or even microswitch hall effect .
What was inside the small card edge terminator for external video? Any ideas?
Im a new subscriber and I'm somewhat happy I found your channel.
That second sensor is for read-write protection disk label!
Re: the 'Batt' connection,there was an aftermarket battery unit for the Osborne 1. If memory serves me correctly, it was a large lead rechargeable battery housed in a case that was at least as heavy and bulky as the computer. The battery allowed for about one hour of standard operation. As you probably guessed, this optional battery pack wasn't popular, and I'm unsure if any survived to today.
I love the metal bars under the keyboard
Osborne spelt correctly! Yes! Top video Dave as usual!
I think one of the reasons the keyboard is that big is because you were supposed to prop up the machine on the keyboard, as your picture shows around 5:39. I have one of these Osborne 1's myself which I am trying to restore. For now it just blinks and beeps continuously.
The ext-video socket is to hook up an external monitor and the cartridge that sits in that slot acts as a loopback so that the internal monitor works. Without it, no video whatsoever.
The RCA socket looks like a third party modification as my unit doesn't have it.
Great teardown though, learned a lot :)
my dad still has one, serial number A06128. still works and has the software disks, only issue is sticky keyboard keys as it's been sitting in storage for a while... with some fiddling around inside the keyboard we got it unstuck so it wouldn't register the "stuck key" on boot up. my mom used it in college though there is NO word formatting like what you'll find in even the basic Notepad today, you had to do ALL the word formatting yourself so that it wasn't all on one line when you went to print(basically formatting in the "word wrap" function manually). came with a 4kb modem!
Here in Brazil we used to have many semiconductor facilities of many brands like TI and also a 100% brazilian one called SID, established, here in my town in the 70-80's and up to 90's I think. Unfortunately, due the lack of incentives from bad government, and the high costs of operating here, including work laws that require from companies a lot of expenses and high taxes, the brands left Brazil for other more competitive countries like Mexico and China. SID, our only local semiconductor company, couldn't hold up and went bankrupt in 90's. It's a shame such a huge company that don't do even a NPN transistor or 555 as we used to.
My dad got one when I was 12. I used it in college in 1989. The floppies would randomly develop errors and Id have to tear it apart and clean the edge connector for the floppy cable. I had an external CRT for it too.
24:30 Single Sided floppy disc drives were radically WAY easier to build in production. The lower head is fixed on the lexan carriage and biased mechanically about 6 to 16 thousands of an inch ( .15mm to 0.41mm ) into the plane of the mylar floppy disc. ie the penetration as we called it in the drive business.
With a double sided drive the top head is gimbaled and the penetration is less and the tolerances need radically WAY tighter.
ie the recording heads will have modulation if the penetration is off and with a double sided unit the top head often is in trouble if the carriage is high or low a tad. With a single sided unit the MPI unit often used Rabbit hair on the non used top brush head, the hair was aligned with the rotation direction.
With a single sided floppy disc drive the tolerances of the head to the media could be crude as can be; with a double sided unit they had to be 5 to 10 times tighter.
In production a double sided unit would often have modulation on the top (gimbaled) head. The production line folks would then often bump up the bias spring on the top head, this would make a unit "pass" read / write; but often fail in the spindle drive current test area. The proper way to fix the mess would be to shim the carraige rods or start over with a new mix of parts. Often in high production units got shipped that worked but had tweaks that made the units wear the floppy discs more, eat heads and make belts slip too.
Besides modulation of the read write signal due to mechanical tolerances a double sided unit had two heads that had to be aligned to reference floppies.
The production cost of a double sided 5 1/4 head carriage was about equal all the other costs in the drive combined . ie castings, PCB, stepper and brush spindle motor
3beltwesty yeah, using ss sd floppies was basically about building down to that low, low price. A floppy drive was NOT cheap.
It was my first computer, no software except CP/M and some Pascal version was included in the deal I got. Great tool for learning programming even if it was a long way from the IBM XT's that my friends had access to.
11:00 Using two EEVBlog multimeters to hold the whole thing. Beauty !
25:55 Looks like flux capacitor (somehow)
The first portable computer is IBM 5100, introduced in 1975.
1982, Bosses at Hughes Aircraft Co wouldn't provide funds for an Osborne, so we build a computer in the lab and used CPM programming with wire wrap and gp boards. Motora chips as I recall, Chips 6810 etc.. Hardest thing was to program was the TTY interface. Later they purchased an IBM PC and gave it to the managers secretary for proposal letters.
FYI @~25 min that sensor would be for write protect cut out not just if disk inserted.
at 22:10 did anybody else notice the black wire from that "mess" of wires actually goes UNDER another part? (marked as C82 on the board)
and at 16:11 if you follow the light blue wire up and kinda left it too goes under another part? (marked at part R13 on the board)
While punching millions of lines of code in basic into my commodore VIC 20 to play some game that probally wouldn't work because it was a comer instead on a full stop......This thing was the future.
Neato! Isn't that second sensor on the drive for the read only cut out thing?
Love it.
Lots of wires in there flapping in the breeze
As one of the people who were part of the Homebrew Computer Club hobbyists of the time - coulda woulda, shoulda - that's just what we had at the time.
I remember when I saw this in BYTE (or was it in Elektor... or Practical Electronics)... and wanted it so MUCH! :)
Thanx for this one, Dave...Old computers...the best ever...for sure!! everytime!!
you can find CP/M on the net...i donwnloaded it somewhere a long time ago...shurely you have to put it on a 5 1/4" floppy somehow....
The 50/60 markings on the disk drive flywheel are actually Hz markings. they were designed to be calibrated with a mains connected neon lamp.
I bought one of these back in 1981. Paid for it before it was released. Used it in my business for a few years before it stopped working.
Since the carry handle is on the other side of the Osborne, I wonder if the 'space' in the keyboard section was also part of the shock absorbing design - in case it was dropped CRT down?
it was 1987 and i was only guy at school who owned an IBM PC Convertible with a color dot matrix printer. The only sad part is it was a bit heavy to carry. Greetings from Chile.
Osborne was great in the day. It was a real step up from my Sinclair. It had a real full size keyboard. I also purchased separate a modem, a parallel printer cable, and an external video adapter that was required in order to get external video. I still have both today. As the Osborne was designed there was a real scramble to find all the parts to make it work. You can read a little about this in the book "Hackers" by Steven Levy. The processor was 8080 or the Z-80 made by Intel but they used what was available and had to use Motorola chips for addressing the memory, which was a little different than if all Intel chips had been available. As far as wiring, at least they had progressed beyond wire-wrap. Quite the machine in the day and it served me very well on several projects back then.
The printer cable cost $40. I made my own with ribbon cable, an edge connector, a hack saw (for the notch) and some epoxy to hold it together after the surgery. Hard core.
25:27 I believe that sensor is write protect and not disk present as you indicate.
You tape over the notch on the side of a 5.25" disk to write protect them.
Why dont you use hydrogen peroxide on the case? I mean for the looking effect, it could be amazing