IBM PS/1 2011 Pt 1: Vintage home computer teardown

[@artype211]

Very good description. I ve got this same model.

[@fooglestuff]

I hope yours works well! I've got a few issues to address, which I'm looking at in upcoming videos.

[@vwestlife]

These PS/1s are compatible with PS/2 floppy drives, including 2.88 MB drives, although the DOS 4.01 in ROM only supports up to 1.44 MB disks -- you need DOS 5.0 or higher to support 2.88 MB disks.

[@fooglestuff]

@vwestlife thanks for the tip, and thanks for stopping by. I've enjoyed a lot of your videos. Now if only 2.88 MB drives were more common! As a kid, I remember being amazed that capacity was possible.

[@Illumenatrix]

My first PC. A lot of older games ran too fast. The floppy drive did something like format 720k disks as 1.44 without drilling them. Played a lot of Wing Commander, and dialed into local Bulletin boards, ours had a 2400 baud modem. My dad purchased this at Sears in 1991.

[@fooglestuff]

Ah yeah… I would’ve been hooked on 2400 baud in 1991. My first BBS experience was in 1992. I never had a PS/1 in the day but it always looked pretty slick and pro to young me ;)

[@Marco.Teixeira]

Very professional video filming. You seem to be off to a good start. Keep it up. I have one of those myself that i'm restoring. I will let you go ahead and and follow your footsteps :)

[@fooglestuff]

Thank you for the great feedback Marco. Good luck with your own restoration. I should have another video up soon that looks at floppy drive repair/replacement options.

[@EricJohnson-fh8zj]

​​@@fooglestuff Idk if it's actually filmed using vintage equipment or if it's just a filter effect....but either way the entire production feels period correct 😆 Great job! 👍

[@fooglestuff]

@@EricJohnson-fh8zj I’ll take that as a compliment even though it was probably just dodgy lighting and an unsteady camera that gives it that look ;) This video actually just started out as a quick experiment but grew beyond that. I’ll keep upping the production values as I get more time to work on future videos! I’m working on the 4th now and I’d like to get into some more serious electronics hacking soon.

[@McTroyd]

New sub for this video series! I have a Model 2011 which hasn't seen a moving electron in a couple decades at this point. Thanks for this deep dive. I may try to find that RS-232 card, because a 2400 baud modem isn't so useful these days... 🤪👍

[@fooglestuff]

Welcome! I hope to get back to making more videos soon, but in the meantime I hope you manage to make progress on getting your own machine up and running. As for the RS-232 card, thankfully the hardware itself is pretty simple so for someone with enough electronics skill it could be cloned on the cheap. I might try that at some point in the future… hmm…

[@McTroyd]

@@fooglestuff Yeah, I haven't taken a look at the service manual. Hopefully it has a pinout for the expander they use for the ISA card slot. That would be cool.

[@fooglestuff]

@@McTroyd The IBM Tech Ref manual is good, found near the bottom of this page: ps1stuff.wordpress.com/documentation/ibm-ps1-model-2011/ -- Section 9 is serial interface & adapters. To me a much more interesting project is attacking the ACU slot: That's at the end of the appendix, and includes a pin-out. It LOOKS like an old PCI slot, but is more like a 16-bit ISA slot with a weird pin-out, and was intended to be used only with the rare "Adapter Card Unit" housing that stacks on top of the chassis. I've had a prototype PCB made that fits it, but I haven't yet tried to make a project with it. That will come later :)

[@McTroyd]

@@fooglestuff I look forward to the results then. Thanks for the link!

[@DavidWonn]

I grabbed one of these in a thrift store for $5. Unfortunately at the time, I didn't know I needed a matching monitor for its power source. D'oh!

[@fooglestuff]

There are options for a power supply if you’re willing to do a little hacking. Some people make their own power supply with the required 36V output, but that’s a bit involved. There’s someone else who also made a board to replace the internal switch mode regulator board, allowing use of an external ATX power supply. All a bit of mucking around though.

[@Dark.Shingo]

I had a 286 one my uncle gave me. It had the memory expansion so it had 1024 kb memory IIRC correctly. Later he gave me a soundcard but it was a propietary model from IBM that couldn't find out what was compatible with, since just a couple of games I ever played on it had sound besides the PC speaker. Good times.

[@fooglestuff]

This is a very late reply, I’m sorry, but yes! There was a very specific sound card for it that was similar to hardware in the Tandy 1000 IIRC. Those cards are quite hard to come by and valuable now! I’m working on an ACU card for supporting regular ISA cards

[@u2370]

These IBM PCs never really made financial sense to me, but a few decades later... cool stuff to look at! Also, your videography and sound are quite nice! A very pleasant watch.

[@fooglestuff]

Thanks for your encouragement! I'm probably putting too much time into production but I'm glad it's appreciated. I agree; I vaguely remember back in the day that they seemed stylish and professional, but at the same time exotic and expensive compared to all the other affordable PC clones. I only now get to see, looking inside, that especially this model was quite crippled and proprietary. It does make it interesting and different to tinker with, though, and I'm hoping to work on some homebrew hardware projects for this machine soon.

[@u2370]

@@fooglestuff Good thing you replied; I hadn't subscribed! That's now fixed :) I've never seen a PS/1, but a rich friend of mine had a PS/2 and I think my school had one PS/2. I remember marveling over the insides of the PS/2 machines and their IBM "solutions" that made the PCs basically un upgradable. I also couldn't wrap my head around why people poured their hard-earned money over what was a mediocre PC. Well... IBM PCs are now history, so I guess most people shared my view!

[@keycontroller]

I remember the sounds lol 😂 even played prince of persia on it the diskete the drive like it is not connected (bad drive/flatcable reversed pin 0)

[@fooglestuff]

@@keycontroller Great PC speaker sound! With the floppy, it's complicated. In part 2 (kzbin.info/www/bejne/oZDRaHmulqefp5o) I first fix the CMOS chip to help store FDD settings, then in part 3 (kzbin.info/www/bejne/jovFaoqElNpjj6M) I repair corrosion in the floppy.

[@fooglestuff]

@@u2370 Oh yeah, it seemed strange back then, and totally foolish now. IBM's MCA seemed fancy, but just made it difficult for everyone. My original exposure to all this as a kid was through a guy that sold IBM PCs, and even he ended up abandoning them in the late PS/2 and PS/1 era. Well, with this oddball PS/1 I hope to do a few more experiments and hacks yet! Got a bit more refurbishing to go yet.

[@peterbrown6224]

I only ever *saw* one of those, and I haven't stopped running away 🙂 Still, what would I know? My 386DX Osborne clone cost $4000, and was an unmitigated piece of junk. Cold solder joints on the motherboard, which I'd sometimes have to shove in the freezer so that it would boot.

[@fooglestuff]

Ah classic :) I love the freezer treatment. Amazing how much they got away with charging for clone stuff with such average QA standards. I’m guessing that’s $4000 in late 1980s dollars too. I have a computer magazine from 1990 discussing the PS/1 launch, and one ad has a bog standard mouse (for example) listed for $160. Crazy!

[@OmegaWolf747]

The PS/1 came out AFTER the PS/2?! 😮

[@fooglestuff]

Sure did! Odd marketing choice, hey? ;)

[@giovannivaccalluzzo4627]

My first PC

[@fooglestuff]

Very nice :) I never had one of these when they were more common. This one belonged to my wife when she was young and she has been delighted to see it starting to work again.

[@paulovicente4929]

Thank you so much for this video! I was wondering if you could please backup its ROM for the IBMulator project and maybe do a backup of the HDD files. I contributed some UK sets to the IBMulator site but i'm still missing some files. Thank you so much for your time and any help on this!!!

[@fooglestuff]

Despite the hiatus, I will get back to this at some point :) I will try to dump and share the ROMs and see what I can do about the HDD too.

[@paulovicente4929]

@@fooglestuff That's great news! I think the BIOS on your PS1 is different from the ones on the ibmulator site. Thanks again!

[@AL4NGDROE]

What was the operating system on these? It was Microsoft but it wasn't windows. It had a folder system but the were stacked on each other with a tab showing at the top. Like a filing cabinet.

[@fooglestuff]

Actually most of the core OS stuff is not from Microsoft but IBM. The PS/1 model 2011 and (I think) 2121 can boot IBM's PC DOS 4.01 from ROM and automatically launch into a simple GUI which is called the "4-quad" screen that includes the "filing cabinet" folders view you described. The ROM also includes a small memory-disk which includes a few basic utilities (though oddly not the one required to do essential config of the system). Typically, though, they will be configured to boot to whatever OS is installed on the hard disk, and while this is usually also PC DOS 4.01, it can be other things just like any regular PC of the era.

[@ambulatorioveterinariodott3768]

Hello, thank you for this nice video about this great looking machine. I have the 2121 from 2011 and would like to restore it and maybe expand. Do you think I can install a bigger drive instead of the 30mb one?

[@fooglestuff]

G'day @ambulatorioveterinariodott3768! Apparently your IBM PS/1 model 2121 uses IDE for hard drives, i.e. PATA (Parallel ATA). I think this means finding a larger drive might be a little easier. Maybe you could use a cheap Compact Flash IDE adapter (e.g. amzn.to/3Ii1GSo) with a small Compact Flash card (e.g. amzn.to/3VJ95Nw). NOTE: The BIOS will probably still limit you in some ways. For more information, read about half-way down this page where it talks about IDE drives: ps1stuff.wordpress.com/documentation/ibm-ps1-model-2121/ I can't test this myself: My model 2011 uses a variation of what's known as XTA, which is quite rare, though I'm interested to see if there's a way to make a smart adapter for this... perhaps in a future video. Let me know how you get along!

[@denniscarrion746]

Beautiful computer I have one but it recently died not sure if it's an easy fix or not

[@fooglestuff]

I hope you manage to work it out. As mentioned at the end of my video, ps1stuff.wordpress.com is a good resource. Maybe my other videos will help too. Does yours still power on, but just not boot up or show anything on screen?

[@denniscarrion746]

@@fooglestuff in my case the computer won't turn on at all it makes a click sound when powering it on and nothing else happens probably power supply issue

[@fooglestuff]

If you plug in your monitor to mains power but detach both cables from the computer base, does the monitor itself power up? If I do this, the monitor power light comes on, there is a fan quietly whirring inside the monitor, and the CRT shows flickering white. If for you this also just clicks but shows no other signs of life then yes, it does sound like it would be a PSU issue.

[@McTroyd]

@@denniscarrion746 There can be a few hundred volts on a switching power supply. But, if you do some research, and take care not to shock yourself, switching power supplies tend to be a really straightforward fix. IBM in those days had some of the best service manuals there were, and might even have a schematic for that power supply if it's on that Wordpress site.

[@geggion]

Nice video! I have the same computer but when I start it up, it gives me the "Incorrect DOS version" error after bypassing the CMOS errors. It runs on IBM DOS 4.00. I can't run most of the programs and commands (mem, format etc.). Also I don't have any floppy disks so I don't know is the floppy drive working. I don't know much about those things. Is there any way to fix it? Apologies for bad english. Thanks! NOTE: I found this pc from our basement. According to what my dad said this computer hasn't turned on since 1997.

[@Juutuub1969]

Thanks a lot for the well done ps/1 videos. I have the same computer, Finnish version of it. I am the first owner of it. Mine is still working after Dallas RTC battery hack. But I wonder, is it anyhow possible to replace the hdd, or is it just non-standard? kzbin.info/www/bejne/hqXRXnWia5dnaKs

[@fooglestuff]

Good question. It might be possible to do something about the HDD, and I plan to investigate this. It will require a custom solution. I think the model 2011 HDD interface is based on the rare “XTA” which is similar to IDE but 8-bit, so not directly compatible. Plus, IBM’s cable is wired a little differently, to integrate power too. I suspect a modern microcontroller could easily adapt or emulate a drive for this interface, so that’s what I’ll try out in future. Another option is the XT-IDE card, but using that will require an ISA slot adapter for the PS/1’s ACU slot, plus a modified PS/1 BIOS (ps1stuff.wordpress.com has one, but not much info yet). These are all things I hope to try out in future videos :)