As did I. Programming on the PDP-8 was my first exposure to programming. From there I decided I wanted to know how computers worked, so I became an EE.
You, good sir, have the patience of a saint. I used to loathe having to learn to configure 5 things right before getting the one thing working I wanted. This brings back my nightmares from the 80’s..
Dave, I wonder if you can appreciate how it feels to see a MS soft engineer trying to do the things I did, back then routinely, working for DEC Field Service. I have a five-digit DEC badge number.
"ask me how I know..." ouch. Such a grand adventure. My high school had an older model of a PDP-11 from early 80s, far before any miniaturization. The hard drive was as large as the system cabinet itself, and was maybe 80 megabytes in capacity spread across 8 large 14 inch heavy drive platters. So far we have come.
I enjoy your videos because I get to be reminded how much I have forgotten (and how much I never knew). My college had a PDP-11/34a running RSTS/E that I was allowed to perform some administrative tasks on (primarily backups). Due to that gig, I was hired by another college to be the sysadmin for its PDP-11/44 running RSTS/E (as well as teaching some classes); I loved those two years. They subsequently bought a Prime computer, I moved to a different job, and my interaction with DEC disappeared. 38 years have passed, and VERY little memory remains, but every once in a while, something will display on your screen that triggers a sweet thought. Thank you for that.
I was a student and a tutor on a PR1ME system back in the mid 1980's. We had in the lab around two dozen Soroc terminals. It was an interesting system, that I almost got kicked out of school for exploring a bit. Came in handy later though, I was able to help an advanced student in testing his security updates.
I enjoy taking some of these information videos and askng my CS students to discuss these early machines and how they influenced the development of the newer machines.
3:30 - this lesson is true in life too. "Not all slots are equal, however, some slots are more equal then others" 😂😂😂😅😅😂 Figured this out through a series of ex's until I met my wife (10 years married in 4 months)
Seeing the wire wrapped backplane brings back memories. As a young service engineer in the early 80 i had a 11-34 and several CM4 (the russian version of 11-40 with even older production technologies. The plans and some old machines to produce have been sold by DEC themselfes to Electronmash in Kiew). We had these CM4 transported to West German city Duesseldorf and send back to Kursk after finishing the programming a steel plant. Remember to open the CM4 and see the golden wrap pins with some corrotion. According was the reliability of these machines....
I love all your content Dave! That series about PDP 11 is living history. Imagine what such a system would have cost back in the days and what level of high tech it has been. Now your phone in your pocket has more computing power than this machine, but nevertheless it’s incredibly fascinating seeing such tech come back to life 😍 Thank you, keep going!
I took a course like 25 years ago in high school. The teacher brought in a box of weird looking boards and taught us to solder using these as practice. I never knew what I was destroying until now after watching this video.
I didnt think id be into these old computers but they really show the evolution of computers and their components we just take for granted and dont have any real understanding. So this really clears up holes in knowledge we've just accepted, like the bus is actually a phsyicall thing connecting everything? Youd never know that building modern computers all day. Now these high level words like DMA make sense, once you udnerstand whats going on with the hardware. Same with the FPU, its just in the blackbox cpu, everything is there and just works, and I dont understand a thing. This helps undersatnd whats going on, and actually doesnt really satisfy to be honest. I want more! I want to see how the CPU moves those bits in slow motion. But at leaste i know the FPU used to be on 5 cards, lol, my 486 didnt have an FPU... and my doom2 fps suffered, i dont want any kid to go through that, so please keep teaching. Thank you.
I love these PDP-11 videos. It reminds me of the 80's when I used to run and program on (3) PDP-11/60's and a PDP-11/84. We used RSTS and RSX-11 for an OS. Somewhere in my garage, I still have some printouts from the system consoles which were all dot matrix terminals. The users had VT100, VT52, and VT220 terminals. Those old computers sure could suck up some power (all 3-phase), and generate some heat.
You're living the shared dream.... but, at the same time, rather you than me! Love watching the summaries and outcomes but I wouldn't have the fortitude for this myself 😅
Love the PDP11 video. Brings back memories of trying to keep a pair of PDP11-34A running in the power station I use to work. Ended up building a third rack to test cards, learnt a lots at the time mostly forgotten now. Carry on the great work.
Thanks, Dave! This brings back so many wonderful memories of my time in the Iron Lab (where all the IBM 360s and PDPs were kept safe from the hordes of SW students...). It was such an honor to be trusted to mount tapes and/or drives in those days...
The Amiga used a DIP Dual In-line Package (two parallel rows of pins) 68000 while this one shown (11:53) was a Pin Grid Array style (pins underneath chip) . I think the DIP version of the 68000 was among the largest DIP chips made with 64 pins. After that it made more sense to put the pins underneath or along the four sides.. Edit: looking back I believe this 68000 is actually a quad flat package type. Leads extending from four sides.
@@marcusdamberger Yes. Same family though. I may have mutilated a pin or two in my younger years. Oh,.. and those chipset names! Agnus, Paula, Denise. Four channel audio in stereo, 4096 colors blasted through a CRT. I never wanna go back lol.
Throughout high school I grew up on the PDP 11-70. It was running RSTS/E which is something you should look into getting your machine(s) to run. If you can actually find and run RSTS/E you will be able to support multi-user environments with DEC basic. Even the base OS programs were written in basic. I remember "hacking" and setting programs to run with high privileges by using the PIP program to set the permissions to in order to get the programs to run. I seem to recall that any account that started in the 1,2 directory also indicated by putting a $ if front of the program name would run that way. I used to run $money which would show the permissions and time used on each account. It was a lot of fun. I think the actual terminals were serial and connected via RS232 if I recall.
Yes, it would be great to have RSTS/E running on this PDP-11/73. I used RSTS/E quite a bit in the 1970s/1980's. Later systems had several RM05 disk sub-systems attached (each 12 platter 256 Mbytes). You could tell how busy the system was by how strong were the floor vibrations from the disk drives!
This is a flashback... I remember this stuff from school from what seems to be centuries ago. I remember setting these up with BNC connectoris on token ring.
I love your PDP-11 videos. I'm not that interested in old mainframe stuff, but your passion and willingness to explain archaic/specialist tools and concepts. I've played with some old systems and tinkered with some MS-Dos and Win 3.11 systems. But my hardware skills top out at understanding the master/slave jumpers on old pata drives. Thanks for taking the time and effort to explain these old workhorses.
Why is this so interesting? It’s like I’m listening to Sherlock Holmes’s describing a tricky case, I have no idea what’s going on but I’m staying to see the finale.
The PDP's were before my time but I have booted a Solaris box from a 1x SCSI CD drive back in the day. Painful memories. Thanks for the video and trip down memory lane.
I'm not a professional hardware or software person (though, I do write substantial code in my field), but even my limited knowledge got me obsessed with minicomputers lately. I wish I'd paid enough attention when these things were still in widespread use. Looking forward to the next video, Dave!
This is fascinating Dave. I came into the PC world after the IBM PC in about 1986. I was taking a class for basic accounting and that machine used WordStar and I believe the Lotus spreadsheet, all in DOS 3.3. My first computer experiences were on Radio Shack TRS-80s, a model 1 and Model 3 in my 6th grade year. I loved this information and of course, my skillset today is UNIX and Linux with a more experience using Macintosh. Of course, a side note is that I was using Apple II series computers all through high school, specifically, the Apple IIe up until around 1990. Where I came upon a cool little IBM box called a PS2 in college. I at that point was really good with DOS and ran a BBS system. Thanks for the great video.
35 years ago I had to build Microvax spares for a system we deployed in Europe from scratch. Much easier than your 11/73 because all the config is done in the DCL monitor, though you do have to set all the dip switches on the cards correctly. The VMS version was new enough that getting the new hardware working was straight forward - again MUCH easier than building kernels.... Brings back many memories - thanks.
I really enjoy all your PDP 11 videos. This was well before my time, but watching you work through getting them up and going is really giving me a sense of what it might have been like to be active when these were *the* computers. Thanks for these videos. Great stuff. :)
Dave. I loved the deep dive! Thank you for all the detail and why things are done the way they are done. I can't wait till you move on to your next "system" I'm voting for you to dive into the world of NeXT and the hardware there! Not to mention the software!! Thanks for doing what you do!
Thanks for the nudge, I've actually been kinda obsessed with POST ROMs on the PDP computers, specifically with running them in simh. I think I found the chip files, now I just gotta figure out where they go.
*I was **_literally_* in love with the PDP's in general, and the 11/34 and 11/70 (and it progeny, like the 73) in particular! I tried getting into a PDP shop for years, although I ended up stuck in my DG Eclipse s/300 instead. When the late versions of these machines came out, I was already running a homebrew Z80 system which nearly matched the capabilities of the 11/70. The machine I wanted to work with more than anything in life was a *_huge_** 11/70 being used to run a perfume factory in New Jersey, but alas, I lost out to another candidate. Working with these old systems were an art form, not a science, and TBH, I miss that period intensely!*
I cut my teeth on TTL chips, and boy oh boy, each one of those boards you present make me hear "Cha Ching!" in as far as power budget was concerned. That power supply must be a mega-beast!
And again, the way back machine takes me back to my days in the US Postal service. We had so many PDP11s because they worked so well. But, the guys in IT got lazy and insisted on moving us to Intel. It all started with a custom board with an Intel 386 chip and 32 kilobytes of static ram - STATIC RAM. We loaded every address and PO mail box in the United States on the static ram memory so that the Intel chip could search memory locations without having to wait multiple clock cycles for each look up. Each machine had two of these $10,000.00 boards so that the poor PDP 11 could take a picture of the address block, send the image to the OCR decoder to convert the image to ascii text, then, flipping back and forth between each Intel board, sending the ASCII address and retrieving the unique 9 digit zip code so that we could spray a bar code of the zip code on each mail piece, flying through the machine at 10 pieces per second average. If we lost power, or if the Intel boards crashed, it only took a couple of hours to reload the address file into static ram through a serial cable. This was the late 80s guys.
For those that don't speak M numbers, M3104 is a quad-height DHV11 asynchronous multiplexer which provides eight full-duplex asynchronous serial data channels on Q-bus systems. It supports baud rates of up-to 38400 although the fastest throughput is 19200 with a maximum board (across all channels) throughput of 15000 chars per second.
when I started at Agriculture Canada, there was a PDP 11. We digitized soil maps. The PDP was connected to four digitizing tables. It wrote the data to a tape which was then sent to an IBM mainframe where the topology was created. The operating system on the PDP 11 was RT-11. I had very little to do with the PDP 11. In 1986, Ag Canada bought ESRI’s Arc/Info which ran on a VAX. It replaced the PDP 11 and the IBM mainframe.
Not to nerd out too much, but that drive ST-4096 has a beautiful sound when it first comes up. The 386-25 that ran on the PC at work I used (about 1990-92) when performing a long run (design rule check on a large schematic, Orcad SDT) the whole table would shake when those heads stroked. There's a video on YT of the sound of the spin up, so stop laughing it wasn't just me that got their ya-ya's out of that monster.
I enjoy your videos on these machines. I never had the chance of working on the hardware. My university had some Digital Vax 11/780s. I did quite a bit of typing on a 3270 terminal. Once in my IT career I worked on quite a few xt machines and 3270 terminals. I replaced quite a few connectors on thick net and thin net. I’m trying to remember the debug addresses on the mfm and rll controllers. I think it g=c800: then a number of which I don’t recall. Those old drives did have some weight to them.
In 1980 we used many PDP11/34 (128 KW of 16 bits) to control circular vector displays (26" / 66cm) for an European Air Defense System. The colors were red, green, yellow and orange. DEC never sold so many mini-computers for 1 project. The system has been built deep into a mountain. We used RSX-11S, the disk-less memory-based version of RSX-11M and the complete system-image was booted over our coax communication link (1 Mbps?).
I remember my first job in 1987, they had some PDP 11/34s and 11/84s for specific purposes using customer software booted from tape, so no RSX/11. On a tidy up, had a whole load of unibus cards in drawers which needed to keep out of the way so the one place I found to put them were actually in the PDPs, so literally filled up unused slots and put a terminator card in front of them so they weren't picked up - fun times. Also having 4 wire leased lines up to the goonhilly satellite base station for data transfer over satellite when required but that's another story.
I got into IT just after my company’s last VAX was shipped to the great bit yard in the sky. The last PDP was gone a decade before that. But some of the old timers and their stories were still around.
I once worked on a PDP-11. lol. There were multiple people using CAD/CAM Unigraphics programs (Drafting), running on the PDP-11, in the 80's. So in that respect, it was an impressive machine back in the day. But, weird enough, we had "hot seats", because, employees were 24/7, so, when I got out of the chair, and was leaving for the day, someone else was sitting in the chair I was leaving. I had no desk, to call my own, and there was only an "inbox", if I came in when someone else was in the chair. I could not come in early, because someone else was in the chair. And the "inbox", was physical, a real box. I lucked into the position, because I knew the man whom was running the temp agency, and I was a high school student with a drafting course under my belt. So, I took his course, which was not a course, as much as an extending two week interview, and I think only two of us finished the course, and were "hired" in the temp position.
I was a user/system admin for a number of PDP 11 systems in the mid-late 1980s. Started with a PDP 11/23 that had a pair of CDC Hawk drives (10MB internal, plus 10MB in a removable platter) each. It had 1MB of ram. We also had a programming station that also had a PDP 11/23 with 2MB of RAM, and an ST-506 drive. This was all on Genrad In-Circuit testers (the first PDP 11/23 was on a Genrad 2270, the programming system was a Genrad 2293 with a pair of VT100 terminals), all running specific software under RSX/11M+. The In-Circuit tester was changed over to a Genrad 2276, and that came with a PDP 11/73, very similar to the one you are working on. Eventually, all of this got replaced by MicroVax systems running VAX/VMS on the newer In-Circuit Testers, and a Vaxstation 3100/30 programming station also running VAX/VMS. When you finish your PDP 11 project, I'd love to see videos on the Vax systems as well; not the "big" Vaxes, but maybe some of the Microvax or Vaxstatiotn type systems. DEC did offer a number of them.
Now you should try to find an E&S Picture System, which ran on the pdp-11. That was a beast of a graphics device. We used it at NASA to plan fly-by's of Voyager, and also to help create the fly-by CG movies that some tv-news at the time thought were actual pictures coming from the spacecraft.
I never got into any sort of ---ix while I was working on PDP-11, it was RSX-11M, RSX-11S, RT-11, RSTS/E and even ancient DOS-11. My employer had a bespoke key-to-disk PDP-11 o/s which used DOS-11 for all the admin and I was given the job of migrating that functionality to RSX-11M-Plus. That involved a very intimate inspection, rewrite and conversion of the BOO.TSK. I couldn't do that during the working day when the system was needed so overnight development it had to be.
in the '90s I took a computer repair course at my local community collage, they had us work on PDP-11s... the mass of wire wrapping on the "mother board" was insane (take the back off and you see 4 million pins wrapped in technicolor spaghetti !) not even a year after I was done with the course they switched to PCs
I used to be a factory engineer. We had PDP-11s driving M6800 processors in the factory. Each M6800 was in a multi-card chassis with a perspex door. One Monday none of the factory machines would work. Suddenly I noticed all the yellow card handles were adjacent as were all the blues etc - the cards had been moved from their dedicated slots. A security card had stolen a cabinet key and had moved the cards over the weekend to make them look 'tidy'!
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BSD is lovely, but you really should try RSX-11M for true PDP-11 excitement! A truly multi-user O/S with genuine realtime performance as well. For real excitement try implementing try implementing a driver for an industrial process controller that requires driver overlays! A lovely walk down memory lane - thanks Dave! PS Check out the later Mentec cards - I remember building an 11/93(!) using one - sad to see them disappear. Also I seem to remember a PC co-processor board that would allow you to run an RT-11 image on native hardware. (Bit-sliced FPGA implementation of the J-11 with the full instruction set including floating point, I think.)
Actually a series where you roamed the country in a van fixing pdp 11's for pelople still running them would be quite entertaining. Might be a short series though😂
Dave, Please use static protection measures. Static protection procedures and equipment were developed during the time that equipment was in production because it was a hugely expensive problem for DEC. If you find you are having issues with getting something to work and you just can’t figure out why, then it may just turn out to be one or more of the cards was damaged or destroyed by static discharge. Ask me how I know. BTW: Static damage may not manifest itself right away. It may linger like a time bomb for a later time.
I have an ST-4096 in my 5150. It's a later production version. When I received it, the head lock was stuck. It took several power cycles to get it unstuck but it hasn't given me any trouble since.
Love seeing the old kit being bought to life. I build my first 286 back in the 90s and that had separate boards for everything apart from cpu and ram. 2mb in separate chips, MFM hard drive with separate controller and serial & parallel cards. I can't wait to the see the next video showing how you get the os installed. Does the disk controller have a boot loader in bios?
Hi Dave, great video as usual. I have been through some of the same struggles with my 11/73. I think you said the other day that you were looking for a rack mount front cover for a BA23 case. I’ve got one that you can have if you want it.
"How do you compile the operating system using the operating system?" This is an interesting question, almost a "chick or egg" type thing. Long ago I remember reading the original C compiler was written in C and compiled itself which sounds to me like the same scenario. I hope you get into this in some detail in future episodes. When you said Seagate 4096 I immediately recognized that- an 80MB MFM drive from the real old days of PCs.
I'm picturing a dozen people trying to pull each other off the ground by their bootstraps, and eventually everyone is floating in the air. The gravity of the situation escapes me...
Man, I rue the day when our QBUS hardware was scrapped. Why oh why didn't I keep at least some of it? Oh, I had no room for four six foot 19 inch racks!
Dave, another mini computer company to add to your collection,,,, maybe ? Computer Automation,, made Alpha LSI/2 and 4 10, 4 30 and maybe 4 90 ,, with pico controllers for devices ( called naked minis since they were just a box & cards ) Cambridge University UK, used these machines, Dr Martain Richards wrote something called BCPL ,,(later C ) used by the Alto in early development i believe His students wrote an operating system using BCPL, called TripOS,, which was used much later as the operating system in the Commodore Amega
Ive always loved Unix/Linux-like os's, but im a big gamer and have to stick to Windows for many games. I used to run and maintain my own style of distro based on archlinux, then moved to gentoo and played with Solaris. Nothing gets me more excited than seeing Dave the man himself, working on his old Unix box, the pdp! Loved the intro, love the pdp vids, and love the channel! Keep it up Dave!!
After answering the same questions multiple times, I now make RUclips videos and supply the link to them. I also copy and paste some of my comments on the videos of other RUclipsrs into documents. This reduces the amount of typing I have to do.
Amazing that something made so relatively recently has a 'cpu' made from discrete components living on multiple large sized cards when an apple 1&2 or the cbm pet/c64 from the similar era are 65xx and z80 chips. I would have expected the pdp would at leave have 'clustered' a set of actual cpu chips. Seems like using 4-8 separate boards (5 more for fpu) would introduce lag because the individual far spaced components would slow things down.
In the AS/400, the slots aren’t all equal either. I was asked to install a token ring card in an as/400 at a site I had to go to anyways (pc supprt). The guy back home looked up the wrong model and told me to put the card into the wrong slot. Fortunately, it jsut fried the token ring card and the AS/400 shut down… and it reeked of magic smoke. Best thing was, the AS/400 guy tried to blame me…
Brings back memories my S36/PC days. We lost a hard drive at a remote location, IBM sent a guy out to replace it, reload the O/S and restore from backup. He couldn't get the system up and running and refused to listen to my suggestions, even though I knew they were correct. I ended up flying out with a spare, and sure enough, I got it up and running without having to use the spare. Could have saved me a trip and time if he would have just listened. But oh no, he's IBM and knows everything
@ Oh mine wasn’t actually an IBM guy, just from ‘our’ AS/400 group. Certainly attended a lot of IBM courses (I did, too, haha, certified OS/2 engineer - then, as soon as NT4.0 came out I threw OS/2 out and had NT4.0 installed everywhere. Not because OS/2 was bad, but because everybody was using OS/2 only as a launcher for Windows apps anyways and especially the office apps had a fair share of issues they didn’t have under windows.
Love this. I cut my engineering and programming teeth on a DEC PDP-8a, such a beautiful dinosaur. Thanks for sharing your journey into the past.
As did I. Programming on the PDP-8 was my first exposure to programming. From there I decided I wanted to know how computers worked, so I became an EE.
You, good sir, have the patience of a saint. I used to loathe having to learn to configure 5 things right before getting the one thing working I wanted. This brings back my nightmares from the 80’s..
Thanks, it’s the autism! We do be like this sometimes 😇
Dave, I wonder if you can appreciate how it feels to see a MS soft engineer trying to do the things I did, back then routinely, working for DEC Field Service. I have a five-digit DEC badge number.
I worked on the entire PDP11 family plus the Vax 750 and 780. Never did much on DEC-10’s and 20’s. I also have a 5 digit employee number.
I've said it before but it bears repeating: love the PDP series. The more PDP content the better.
"ask me how I know..." ouch. Such a grand adventure. My high school had an older model of a PDP-11 from early 80s, far before any miniaturization. The hard drive was as large as the system cabinet itself, and was maybe 80 megabytes in capacity spread across 8 large 14 inch heavy drive platters. So far we have come.
I remember those RP04 88MB drives. About the size of a washing machine.
I enjoy your videos because I get to be reminded how much I have forgotten (and how much I never knew). My college had a PDP-11/34a running RSTS/E that I was allowed to perform some administrative tasks on (primarily backups). Due to that gig, I was hired by another college to be the sysadmin for its PDP-11/44 running RSTS/E (as well as teaching some classes); I loved those two years. They subsequently bought a Prime computer, I moved to a different job, and my interaction with DEC disappeared. 38 years have passed, and VERY little memory remains, but every once in a while, something will display on your screen that triggers a sweet thought. Thank you for that.
I was a student and a tutor on a PR1ME system back in the mid 1980's. We had in the lab around two dozen Soroc terminals. It was an interesting system, that I almost got kicked out of school for exploring a bit. Came in handy later though, I was able to help an advanced student in testing his security updates.
Lord, she's a beauty. Thanks for sharing with us the good parts of your PDP journey Dave!
Old tech is amazing. It's great you're telling these stories.
I enjoy taking some of these information videos and askng my CS students to discuss these early machines and how they influenced the development of the newer machines.
and they reply...what's a hard drive (sigh)
3:30 - this lesson is true in life too.
"Not all slots are equal, however, some slots are more equal then others" 😂😂😂😅😅😂
Figured this out through a series of ex's until I met my wife (10 years married in 4 months)
Animal Farm reference 😊
Thanks for rescuing this beautiful DEC specimen and giving it loving home to live its golden years happily humming 🤠🤏
Seeing the wire wrapped backplane brings back memories. As a young service engineer in the early 80 i had a 11-34 and several CM4 (the russian version of 11-40 with even older production technologies. The plans and some old machines to produce have been sold by DEC themselfes to Electronmash in Kiew).
We had these CM4 transported to West German city Duesseldorf and send back to Kursk after finishing the programming a steel plant.
Remember to open the CM4 and see the golden wrap pins with some corrotion. According was the reliability of these machines....
😂 “Ask me how I know” 😂 Absolutely hysterical! Love the dry sarcasm. Keep making these videos.
Another brilliant episode and extremely informative. Thank you Dave.
What I love about Dave's videos is not only does he showcase items from the mid 70s forward, his video clips really cover the same period.
I love all your content Dave!
That series about PDP 11 is living history.
Imagine what such a system would have cost back in the days and what level of high tech it has been. Now your phone in your pocket has more computing power than this machine, but nevertheless it’s incredibly fascinating seeing such tech come back to life 😍
Thank you, keep going!
I took a course like 25 years ago in high school. The teacher brought in a box of weird looking boards and taught us to solder using these as practice. I never knew what I was destroying until now after watching this video.
Hello and thank you for the videos on these old systems
I didnt think id be into these old computers but they really show the evolution of computers and their components we just take for granted and dont have any real understanding. So this really clears up holes in knowledge we've just accepted, like the bus is actually a phsyicall thing connecting everything? Youd never know that building modern computers all day. Now these high level words like DMA make sense, once you udnerstand whats going on with the hardware. Same with the FPU, its just in the blackbox cpu, everything is there and just works, and I dont understand a thing. This helps undersatnd whats going on, and actually doesnt really satisfy to be honest. I want more! I want to see how the CPU moves those bits in slow motion. But at leaste i know the FPU used to be on 5 cards, lol, my 486 didnt have an FPU... and my doom2 fps suffered, i dont want any kid to go through that, so please keep teaching. Thank you.
This is some of the most enjoyable, creative tech writing on the circuit at the moment. Thanks.
I love these PDP-11 videos. It reminds me of the 80's when I used to run and program on (3) PDP-11/60's and a PDP-11/84. We used RSTS and RSX-11 for an OS. Somewhere in my garage, I still have some printouts from the system consoles which were all dot matrix terminals. The users had VT100, VT52, and VT220 terminals. Those old computers sure could suck up some power (all 3-phase), and generate some heat.
You're living the shared dream.... but, at the same time, rather you than me! Love watching the summaries and outcomes but I wouldn't have the fortitude for this myself 😅
Exactly the video I asked for last week Dave! Thanks and well done. Once I get out of the hospital, I will be watching this and much more detail.
I LOVE your hardware videos Dave
Love the PDP11 video. Brings back memories of trying to keep a pair of PDP11-34A running in the power station I use to work. Ended up building a third rack to test cards, learnt a lots at the time mostly forgotten now. Carry on the great work.
Thanks, Dave! This brings back so many wonderful memories of my time in the Iron Lab (where all the IBM 360s and PDPs were kept safe from the hordes of SW students...). It was such an honor to be trusted to mount tapes and/or drives in those days...
Damn,.. been a while since I saw one of those Motorola 68000 chips. I think it was in my Commodore Amiga when I was a kid. What a beast!
The Amiga used a DIP Dual In-line Package (two parallel rows of pins) 68000 while this one shown (11:53) was a Pin Grid Array style (pins underneath chip) . I think the DIP version of the 68000 was among the largest DIP chips made with 64 pins. After that it made more sense to put the pins underneath or along the four sides.. Edit: looking back I believe this 68000 is actually a quad flat package type. Leads extending from four sides.
@@marcusdamberger Yes. Same family though. I may have mutilated a pin or two in my younger years. Oh,.. and those chipset names! Agnus, Paula, Denise. Four channel audio in stereo, 4096 colors blasted through a CRT. I never wanna go back lol.
Throughout high school I grew up on the PDP 11-70. It was running RSTS/E which is something you should look into getting your machine(s) to run. If you can actually find and run RSTS/E you will be able to support multi-user environments with DEC basic. Even the base OS programs were written in basic. I remember "hacking" and setting programs to run with high privileges by using the PIP program to set the permissions to in order to get the programs to run. I seem to recall that any account that started in the 1,2 directory also indicated by putting a $ if front of the program name would run that way. I used to run $money which would show the permissions and time used on each account. It was a lot of fun. I think the actual terminals were serial and connected via RS232 if I recall.
Yes, it would be great to have RSTS/E running on this PDP-11/73. I used RSTS/E quite a bit in the 1970s/1980's. Later systems had several RM05 disk sub-systems attached (each 12 platter 256 Mbytes). You could tell how busy the system was by how strong were the floor vibrations from the disk drives!
This is a flashback... I remember this stuff from school from what seems to be centuries ago. I remember setting these up with BNC connectoris on token ring.
Loved the intro, that was great!
I love the intro Dave!
I love your PDP-11 videos. I'm not that interested in old mainframe stuff, but your passion and willingness to explain archaic/specialist tools and concepts. I've played with some old systems and tinkered with some MS-Dos and Win 3.11 systems. But my hardware skills top out at understanding the master/slave jumpers on old pata drives. Thanks for taking the time and effort to explain these old workhorses.
Why is this so interesting? It’s like I’m listening to Sherlock Holmes’s describing a tricky case, I have no idea what’s going on but I’m staying to see the finale.
The PDP's were before my time but I have booted a Solaris box from a 1x SCSI CD drive back in the day. Painful memories. Thanks for the video and trip down memory lane.
I'm not a professional hardware or software person (though, I do write substantial code in my field), but even my limited knowledge got me obsessed with minicomputers lately. I wish I'd paid enough attention when these things were still in widespread use. Looking forward to the next video, Dave!
This is fascinating Dave. I came into the PC world after the IBM PC in about 1986. I was taking a class for basic accounting and that machine used WordStar and I believe the Lotus spreadsheet, all in DOS 3.3. My first computer experiences were on Radio Shack TRS-80s, a model 1 and Model 3 in my 6th grade year. I loved this information and of course, my skillset today is UNIX and Linux with a more experience using Macintosh. Of course, a side note is that I was using Apple II series computers all through high school, specifically, the Apple IIe up until around 1990. Where I came upon a cool little IBM box called a PS2 in college. I at that point was really good with DOS and ran a BBS system. Thanks for the great video.
Sir, your intro to this video is next level.
35 years ago I had to build Microvax spares for a system we deployed in Europe from scratch. Much easier than your 11/73 because all the config is done in the DCL monitor, though you do have to set all the dip switches on the cards correctly. The VMS version was new enough that getting the new hardware working was straight forward - again MUCH easier than building kernels.... Brings back many memories - thanks.
I really enjoy all your PDP 11 videos. This was well before my time, but watching you work through getting them up and going is really giving me a sense of what it might have been like to be active when these were *the* computers.
Thanks for these videos. Great stuff. :)
Dave. I loved the deep dive! Thank you for all the detail and why things are done the way they are done.
I can't wait till you move on to your next "system" I'm voting for you to dive into the world of NeXT and the hardware there! Not to mention the software!!
Thanks for doing what you do!
Inspiring. Had me on the edge of my seat. The PDP 11 is so iconic. I saw someone has a Rasperry Pi case based on one.
Thanks for the nudge, I've actually been kinda obsessed with POST ROMs on the PDP computers, specifically with running them in simh. I think I found the chip files, now I just gotta figure out where they go.
*I was **_literally_* in love with the PDP's in general, and the 11/34 and 11/70 (and it progeny, like the 73) in particular! I tried getting into a PDP shop for years, although I ended up stuck in my DG Eclipse s/300 instead. When the late versions of these machines came out, I was already running a homebrew Z80 system which nearly matched the capabilities of the 11/70. The machine I wanted to work with more than anything in life was a *_huge_** 11/70 being used to run a perfume factory in New Jersey, but alas, I lost out to another candidate. Working with these old systems were an art form, not a science, and TBH, I miss that period intensely!*
Wow, you are going to the beginning. O.K., this sounds fun, let's do this!
I cut my teeth on TTL chips, and boy oh boy, each one of those boards you present make me hear "Cha Ching!" in as far as power budget was concerned. That power supply must be a mega-beast!
And again, the way back machine takes me back to my days in the US Postal service. We had so many PDP11s because they worked so well. But, the guys in IT got lazy and insisted on moving us to Intel. It all started with a custom board with an Intel 386 chip and 32 kilobytes of static ram - STATIC RAM. We loaded every address and PO mail box in the United States on the static ram memory so that the Intel chip could search memory locations without having to wait multiple clock cycles for each look up. Each machine had two of these $10,000.00 boards so that the poor PDP 11 could take a picture of the address block, send the image to the OCR decoder to convert the image to ascii text, then, flipping back and forth between each Intel board, sending the ASCII address and retrieving the unique 9 digit zip code so that we could spray a bar code of the zip code on each mail piece, flying through the machine at 10 pieces per second average. If we lost power, or if the Intel boards crashed, it only took a couple of hours to reload the address file into static ram through a serial cable. This was the late 80s guys.
I just got an Atari mega ste from the Canadian post office..
What a beautiful machine, wish they still made systems that looked like this .
For those that don't speak M numbers, M3104 is a quad-height DHV11 asynchronous multiplexer which provides eight full-duplex asynchronous serial data channels on Q-bus systems. It supports baud rates of up-to 38400 although the fastest throughput is 19200 with a maximum board (across all channels) throughput of 15000 chars per second.
Thanks Dave. I'll catch up. Someday. Really enjoy your vids.
when I started at Agriculture Canada, there was a PDP 11. We digitized soil maps. The PDP was connected to four digitizing tables. It wrote the data to a tape which was then sent to an IBM mainframe where the topology was created. The operating system on the PDP 11 was RT-11. I had very little to do with the PDP 11. In 1986, Ag Canada bought ESRI’s Arc/Info which ran on a VAX. It replaced the PDP 11 and the IBM mainframe.
Not to nerd out too much, but that drive ST-4096 has a beautiful sound when it first comes up. The 386-25 that ran on the PC at work I used (about 1990-92) when performing a long run (design rule check on a large schematic, Orcad SDT) the whole table would shake when those heads stroked. There's a video on YT of the sound of the spin up, so stop laughing it wasn't just me that got their ya-ya's out of that monster.
LOLOLOL! I was NOT prepared for that intro! :D
I enjoy your videos on these machines. I never had the chance of working on the hardware. My university had some Digital Vax 11/780s. I did quite a bit of typing on a 3270 terminal. Once in my IT career I worked on quite a few xt machines and 3270 terminals. I replaced quite a few connectors on thick net and thin net. I’m trying to remember the debug addresses on the mfm and rll controllers. I think it g=c800: then a number of which I don’t recall. Those old drives did have some weight to them.
In 1980 we used many PDP11/34 (128 KW of 16 bits) to control circular vector displays (26" / 66cm) for an European Air Defense System. The colors were red, green, yellow and orange. DEC never sold so many mini-computers for 1 project. The system has been built deep into a mountain. We used RSX-11S, the disk-less memory-based version of RSX-11M and the complete system-image was booted over our coax communication link (1 Mbps?).
Dave you are a genuine national treasure.
Someone once told me the start up of a PDP sounded like the soundFX of 6-Million Dollar Man. Is that true?
I remember my first job in 1987, they had some PDP 11/34s and 11/84s for specific purposes using customer software booted from tape, so no RSX/11. On a tidy up, had a whole load of unibus cards in drawers which needed to keep out of the way so the one place I found to put them were actually in the PDPs, so literally filled up unused slots and put a terminator card in front of them so they weren't picked up - fun times. Also having 4 wire leased lines up to the goonhilly satellite base station for data transfer over satellite when required but that's another story.
I got into IT just after my company’s last VAX was shipped to the great bit yard in the sky. The last PDP was gone a decade before that. But some of the old timers and their stories were still around.
I once worked on a PDP-11. lol. There were multiple people using CAD/CAM Unigraphics programs (Drafting), running on the PDP-11, in the 80's. So in that respect, it was an impressive machine back in the day. But, weird enough, we had "hot seats", because, employees were 24/7, so, when I got out of the chair, and was leaving for the day, someone else was sitting in the chair I was leaving. I had no desk, to call my own, and there was only an "inbox", if I came in when someone else was in the chair. I could not come in early, because someone else was in the chair. And the "inbox", was physical, a real box. I lucked into the position, because I knew the man whom was running the temp agency, and I was a high school student with a drafting course under my belt. So, I took his course, which was not a course, as much as an extending two week interview, and I think only two of us finished the course, and were "hired" in the temp position.
My first OS, RSX/11. I had a PDP11/23 with a couple RLO drives. We often used MegaLink for "high speed" local network.
PrimOS after that.
I was a user/system admin for a number of PDP 11 systems in the mid-late 1980s. Started with a PDP 11/23 that had a pair of CDC Hawk drives (10MB internal, plus 10MB in a removable platter) each. It had 1MB of ram. We also had a programming station that also had a PDP 11/23 with 2MB of RAM, and an ST-506 drive. This was all on Genrad In-Circuit testers (the first PDP 11/23 was on a Genrad 2270, the programming system was a Genrad 2293 with a pair of VT100 terminals), all running specific software under RSX/11M+. The In-Circuit tester was changed over to a Genrad 2276, and that came with a PDP 11/73, very similar to the one you are working on. Eventually, all of this got replaced by MicroVax systems running VAX/VMS on the newer In-Circuit Testers, and a Vaxstation 3100/30 programming station also running VAX/VMS.
When you finish your PDP 11 project, I'd love to see videos on the Vax systems as well; not the "big" Vaxes, but maybe some of the Microvax or Vaxstatiotn type systems. DEC did offer a number of them.
The plural of VAX is VAXen, not VAXes!
I am simultaneously fascinated by pre-microprocessor computing and thankful that I am too young to have dealt with it.
Now you should try to find an E&S Picture System, which ran on the pdp-11. That was a beast of a graphics device. We used it at NASA to plan fly-by's of Voyager, and also to help create the fly-by CG movies that some tv-news at the time thought were actual pictures coming from the spacecraft.
I never got into any sort of ---ix while I was working on PDP-11, it was RSX-11M, RSX-11S, RT-11, RSTS/E and even ancient DOS-11. My employer had a bespoke key-to-disk PDP-11 o/s which used DOS-11 for all the admin and I was given the job of migrating that functionality to RSX-11M-Plus. That involved a very intimate inspection, rewrite and conversion of the BOO.TSK. I couldn't do that during the working day when the system was needed so overnight development it had to be.
in the '90s I took a computer repair course at my local community collage, they had us work on PDP-11s... the mass of wire wrapping on the "mother board" was insane (take the back off and you see 4 million pins wrapped in technicolor spaghetti !) not even a year after I was done with the course they switched to PCs
This is really amazing, bridging the old with the new. A lot of fun!
“124KW OF MEMORY” That’s some power hungry memory! Now that massive generator purchase makes sense.
Why not become a traveling PDP repair guy? Welcome to Dave’s Van!
Gosh darn!! It's been way too long (and not long enough) since I've seen ribbon interconnect cables in a computer. Ah the memories!
{^_-}
I used to be a factory engineer. We had PDP-11s driving M6800 processors in the factory. Each M6800 was in a multi-card chassis with a perspex door.
One Monday none of the factory machines would work. Suddenly I noticed all the yellow card handles were adjacent as were all the blues etc - the cards had been moved from their dedicated slots. A security card had stolen a cabinet key and had moved the cards over the weekend to make them look 'tidy'!
Upvote for the Highlander reference!
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Excellent presentation. Thank you.
Breadboard build with the J11. That would ve a great series.
BSD is lovely, but you really should try RSX-11M for true PDP-11 excitement! A truly multi-user O/S with genuine realtime performance as well.
For real excitement try implementing try implementing a driver for an industrial process controller that requires driver overlays!
A lovely walk down memory lane - thanks Dave!
PS Check out the later Mentec cards - I remember building an 11/93(!) using one - sad to see them disappear. Also I seem to remember a PC co-processor board that would allow you to run an RT-11 image on native hardware. (Bit-sliced FPGA implementation of the J-11 with the full instruction set including floating point, I think.)
Dave, you can help UsagiElectric with his own PDP-11 with all this knowledge.
I love the creative repurposing of pop media film content. ROTFL
Thanks Dave.
Actually a series where you roamed the country in a van fixing pdp 11's for pelople still running them would be quite entertaining. Might be a short series though😂
Dave, Please use static protection measures. Static protection procedures and equipment were developed during the time that equipment was in production because it was a hugely expensive problem for DEC. If you find you are having issues with getting something to work and you just can’t figure out why, then it may just turn out to be one or more of the cards was damaged or destroyed by static discharge. Ask me how I know. BTW: Static damage may not manifest itself right away. It may linger like a time bomb for a later time.
9:25 missed a chance for a "I cannot self-terminate" movie reference. KLANG KLANG! KLANG! KLA-KLANG!
Ethernet on a PDP-11 is like GPS on a Model T! I mean, obviously you can do it, but it's pretty wild😁
Now imagine recompiling the NT kernel every time you add or change hardware. 😁
CuriousMarc might be a good place to start.
Best episode ever!
I have an ST-4096 in my 5150. It's a later production version. When I received it, the head lock was stuck. It took several power cycles to get it unstuck but it hasn't given me any trouble since.
i love this channel so much hahaha
Love seeing the old kit being bought to life. I build my first 286 back in the 90s and that had separate boards for everything apart from cpu and ram. 2mb in separate chips, MFM hard drive with separate controller and serial & parallel cards. I can't wait to the see the next video showing how you get the os installed. Does the disk controller have a boot loader in bios?
loved the intro
Very impressive!
Hi Dave, great video as usual. I have been through some of the same struggles with my 11/73.
I think you said the other day that you were looking for a rack mount front cover for a BA23 case. I’ve got one that you can have if you want it.
"How do you compile the operating system using the operating system?" This is an interesting question, almost a "chick or egg" type thing. Long ago I remember reading the original C compiler was written in C and compiled itself which sounds to me like the same scenario. I hope you get into this in some detail in future episodes.
When you said Seagate 4096 I immediately recognized that- an 80MB MFM drive from the real old days of PCs.
When you said “half width” I kept thinking ’half wit’ card. I thought PDP was being brutally honest.
I'm picturing a dozen people trying to pull each other off the ground by their bootstraps, and eventually everyone is floating in the air. The gravity of the situation escapes me...
Man, I rue the day when our QBUS hardware was scrapped. Why oh why didn't I keep at least some of it? Oh, I had no room for four six foot 19 inch racks!
Dave, another mini computer company to add to your collection,,,, maybe ?
Computer Automation,, made Alpha LSI/2 and 4 10, 4 30 and maybe 4 90 ,, with pico controllers for devices ( called naked minis since they were just a box & cards )
Cambridge University UK, used these machines, Dr Martain Richards wrote something called BCPL ,,(later C ) used by the Alto in early development i believe
His students wrote an operating system using BCPL, called TripOS,, which was used much later as the operating system in the Commodore Amega
Ive always loved Unix/Linux-like os's, but im a big gamer and have to stick to Windows for many games. I used to run and maintain my own style of distro based on archlinux, then moved to gentoo and played with Solaris. Nothing gets me more excited than seeing Dave the man himself, working on his old Unix box, the pdp! Loved the intro, love the pdp vids, and love the channel! Keep it up Dave!!
I've always disliked Linux / UNIX style OSs, but I'm happy to listen if Dave talks.
@toby9999 to each their own, but definitely Dave! 😂
After answering the same questions multiple times, I now make RUclips videos and supply the link to them. I also copy and paste some of my comments on the videos of other RUclipsrs into documents. This reduces the amount of typing I have to do.
Never knew one needed so much halfwits to get a pdp-11 running.
Amazing that something made so relatively recently has a 'cpu' made from discrete components living on multiple large sized cards when an apple 1&2 or the cbm pet/c64 from the similar era are 65xx and z80 chips.
I would have expected the pdp would at leave have 'clustered' a set of actual cpu chips. Seems like using 4-8 separate boards (5 more for fpu) would introduce lag because the individual far spaced components would slow things down.
In the AS/400, the slots aren’t all equal either. I was asked to install a token ring card in an as/400 at a site I had to go to anyways (pc supprt). The guy back home looked up the wrong model and told me to put the card into the wrong slot. Fortunately, it jsut fried the token ring card and the AS/400 shut down… and it reeked of magic smoke. Best thing was, the AS/400 guy tried to blame me…
Brings back memories my S36/PC days. We lost a hard drive at a remote location, IBM sent a guy out to replace it, reload the O/S and restore from backup. He couldn't get the system up and running and refused to listen to my suggestions, even though I knew they were correct. I ended up flying out with a spare, and sure enough, I got it up and running without having to use the spare. Could have saved me a trip and time if he would have just listened. But oh no, he's IBM and knows everything
@ Oh mine wasn’t actually an IBM guy, just from ‘our’ AS/400 group. Certainly attended a lot of IBM courses (I did, too, haha, certified OS/2 engineer - then, as soon as NT4.0 came out I threw OS/2 out and had NT4.0 installed everywhere. Not because OS/2 was bad, but because everybody was using OS/2 only as a launcher for Windows apps anyways and especially the office apps had a fair share of issues they didn’t have under windows.
It's not a real computer unless it takes ten minutes to boot -then reset- and boot again. I am having cyber-flashbacks... wonderful video.