Restoring and repairing IBM PS/2 286 Model 50 from 1987 and installing DOS on a SCSI drive DOScember
ฝัง
- เผยแพร่เมื่อ 9 ธ.ค. 2022
- The first WinTel PC I bought after my Commodore 64 years. Let's restore it back to its former glory and make it into a nice DOS gaming PC
PCB Prototype the Easy Way. Full feature custom PCB prototype service. www.pcbway.com/
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Music by Karl Casey @ White Bat Audio
#doscember #doscember2022 #ibm #ibmps2
Tools I regularly use
DeoxIT D5 Contact Cleaner
Hanstar 861DW Hot Air Rework Station
Pro'sKit SS-331 Desoldering Station
UNI-T UT61E Auto Ranging Multimeter
UNI-T UT890D Manual Ranging Multimeter
PINECIL Soldering Iron
TS-100 Soldering Iron
AMTECH NC-559-ASM Flux
PinePower Charger/PSU
TL866 II Plus Programmer
Tektronix 2246A 100 MHz four-channel analog scope
MaAnt Grinding Pen - วิทยาศาสตร์และเทคโนโลยี
You can make 2 gigabytes partitions in Ms Dos 6.22
Excellent, thanks
On every version from dos 4.01 to at least dos 6.22 you can make fat partitions Up to 2 GB.
My dad gave our first computer to a family that didn't have one when we got a new one.
Damn his generosity, I want my Laser XT and Commodore 1084 monitor back.
haha, well, at least you can still find one of those on eBay. But sure, it would have been nice to find the actual PC one ones had
The Quantum SCSI drive belongs into a Macintosh II. ;)
Thanks, I don't have one of those. I'd better pick one up on eBay :)
@@Epictronics1 haha, buying the matching computer to the HDD. 😂😂 👍👍👍
@@Takeshi.Nakagawa haha, that would not be the first time 😅
ahh the nostalgia...my very first computer was a ps/2 model 50. Since it had only 1 mb of RAM I had to learn about running windows 3.0 real mode just to see what it looked like. I took it into my computer teachers class in middle school and asked him what I could upgrade on it. He must have felt bad for me because later on that month he built me a FULLY LOADED Model 80 tower from the schools spare parts stash. It was a 386/20 with 24mb RAM via a ram expansion card, dual 80mb HDDs and two 1.44mb floppy drives. It was a monster of a machine for its time with all that RAM.
Great story :) I'm not 100% sure, but I think the next Model 50 video is going to be in about two weeks. The Model 80 is quite the monster PS/2. There will be a restoration video of a Model 80 on this channel, Probably around December.
@@Epictronics1 that's awesome, looking forward to the model 80 stuff. Those two machines are what kickstarted my love for computing and led me on a career in IT
My first job; IBM System/38 Programmer / SysAdmin at a TV factory; made me the goto guy with PCs. The HR department had one of those bloody PS/2 model 50's - probably the most nasty box I've ever worked with. That 1.44mb floppy drive on that model 50 never worked correctly; read/write errors all the time. Replaced the drive, the riser, the motherboard... Still didn't work correctly. Even the IBM engineer told us that the early model 50's were ... "crap". In the end we got a free upgrade to a model 55.
(Mind you, I did get something out of it. The original 5150 PC that the accountants used was going to be binned - I nabbed that. Made at Greenock, Scotland... Ultra low serial number.)
haha, Well, my bloody Model 50 worked like a charm from day one back then :) Nowadays they need fresh caps in the diskette drive and a SCSI drive to work. I've got a 55 too, it's a nice machine but there is something special about the early Model 50, just like with your 5150. I hope you kept it btw! I've got two of them, the first and second rev board. I've done a teardown/clean video about the first rev machine but the second rev is going to need a repair video
It might be fun to try out os/2 on one of these machines- thanks for the great videos
Thanks for watching!
I have this machine, Been in my loft since early 90s, Has twin floppys & HD, I know it used to boot but not tested for years now.
It amazes me how much people remember from back then. I only recall buying a second hand computer off a guy back then that ran dos, selling it a few years later for a windows 95 machine with a pentium mmx 133. I thought I was the shit 😂. Going to computer shows for floppy disks with doom wads was the highlight.
Pentium MMX was the shit :)
OMG! My first experience with the PC world was at secondary school. They had two old labs with PS/2 machines. One 286 (for the teacher) and the rest smaller 8086. The noises of the floppy drives and the "squeaky" 20MB HDDs are forever in my mind. "Computer" was not really a thing back in the day, it was not even in the official teaching schedule. But some of my teachers could see the potential so they were allowing students to use the computers in the afternoon. I used to go back to school when the computer labs were open and tinker and learn. Those machines were full of viruses so I remember spending time running antivirus on them. One of them was unrecoverable (at least for my limited skills of the time) so I got a brand new "IBM DOS 3.30" box from the cupboard and very bravely decided to wipe the computer and reinstall it (it was a big thing, for what I knew the PC might have died for good!). That was my first MSDOS installation! :) I'd LOVE to have one of those machines. Thank you for bringing back all those nice memories!
Haha, that sounds like awesome memories : ) We also had the PS/2 Model 30 (8086) at school and I loved it, it had some sort of CAD software and I used it to make very primitive schematics 74xx stuff. I still have one in my collection : )
@@Epictronics1 We were only running Turbo Pascal and Lotus 1-2-3 :D That's it, now I need a Model 30. :D
I wasn't joking! Found a partially working model 30 online at reasonable price... Video coming soon! :D (You'll be mentioned as responsible for my impulsive purchase! LOL) - I'll link your videos for sure!
@@tony359 Oh, man, I remember Turbo Pascal, so much fun : ) Beware of the 286 when you shop for a Model 30. They are very similar : ) I made a video about the original Model 30 a very long time ago here: th-cam.com/video/UQoxZSvicOc/w-d-xo.html
@@tony359 Awesome lol. Good luck with the project!
Old 3.5" harddrives usually don't like to be run upside down. Back then in the specifications you could usually read the allowed orientations of a harddrive.
Thanks for the warning! I didn't know this
Interesting I never knew that. :)
True for the older 5-1/4" drives as well - on the Model 60 and 80, the drives mounted on their sides need to be re-formatted over time. But the drive Roman has is quite a bit newer in design, and the drive platters are dual-sided: One head is "upside-down" while the other is on "top". Unless there is some difference in how the arms of the heads are designed (with the head "flying" above the platters under very tight tolerances while in operation), this is going to be a non-issue.
What I thought was funny about that Computer Chronicles show was when he said he thought having a front power switch wouldn't catch on 😂
that is hilarious lol
Dos 6.22 max partition is 2Gb.
cool, thanks
@@Epictronics1 Probably just have to re-initialize the drive in fdisk to allow for 2GB FAT16.
@@Epictronics1 no worries!
Love your channel from RB Retro Bunker /Sweden 😉
Thanks : )
The Quantum Q250, a.k.a Apple Part Number 76-45004. If memory serves, that was used in the Mac II.
Thanks, I should probably get one of those too : )
Looking forward to more on this system. I recently acquired the same model and these are just a bit before I got into computers, when ISA, VLB, and PCI had already taken over....Even 8-bit ISA is on the fringe of my experience.
Awesome. I will be ordering stuff and keep working on this system for a very long time to come :)
IiSA predates this. MCA was IBM’s attempt to solve two problems: Needing more bandwidth than the 16-bit ISA bus could handle (MCA can be 16- or 32-bit.) And, a closed architecture to thwart all the clones. You can tell how that went over by the massive proliferation of MCA add-in cards.
Nice to see the machine up n' running again! The vertical refresh frequency for the 80x25 mode should be 70 Hz. Oh and Set date and time is under the Set Features menu...
I won't miss it next time lol. I can only do 50,60 and 80 with my camera. Thanks
That 5.25” Apple drive most likely came out of a Mac II or Mac IIx. 5.25” drives were only used in a few Mac models back in the day, and judging by the capacity, that would seem to be the most likely option.
Thanks. I guess I'll start looking for a Mac II with a missing hard drive :)
I'll stick to my 386-powered IBM 5170 with its standard ISA bus, but man that dual-layer graphics card is awesome looking!
It is! Still looking for the matching 8514 Display. What 386 board fits the 5170? Was there even a standard form factor for 286 boards?
@@Epictronics1 Good question! I was wondering if anyone would catch that and ask! I really wanted to keep the original IBM mobo with all its quirks but I needed the 386 instruction set for software I wanted to run so I got an "Intel SnapIn 386" which is a 386sx CPU with a 2.5x clock multiplier and some cache chips on a daughter board that replaces the original 286 CPU. It was expensive on eBay but it's really cool!! And it came with a thick metal badge that says "Powered By Intel SnapIn 386."
@@angieandretti Oh, now that I know it exists, I think I need one for my 5162 lol
Thanks for a great video! As a kid, I was stuck with a PS/2 (of course with the MCA bus) during the the mid 90s. I really came to hate the PS/2 and MCA combo because I missed out on Sound Blaster, CD-ROM, etc, but now I can admit it is fascinating to see what can be done using the resources available today. Keep up the good work, and I hope that you will be able to find a sound card for this machine.
I sort of have already :) Not spoiling anything... Yes, PS/2s are all about the challenge. Thanks!
I believe 500 MB is a limitation of the BIOS for IDE harddrives in e.g. 286 or 386. But since this is SCSI, 2 GB is perhaps overkill, but may still work because 2 GB is the limit for FAT-16B. I'd still do another partition or two.
I can't see enough of the FRU labels on the ROMs - We are still looking for the 9 May 1987 'Revision 1' BIOS (90X6816 / 90X6817 / 90X6815 / 90X6818 is 'Revision 0').
I had a look through the video files but I can't read the labels. I'll have to take it apart again. give me a few days
I've always had a bit of a fascination with micro channel architecture. Never actually had a machine that supported it tho lol.
We were an apple household because my dad could buy them at educational discount through his work, as a teacher. And every time the schools upgraded i would buy the older models they were retiring at next to nothing so I could have a computer of my own.
It's too bad it didn't succeed as a new standard. Some say IBM was charging too much for the license. On the other hand, they make fun and challenging projects nowadays : ) I'm trying to order a PCB now for one of those MCA slots for a follow-up video
@@Epictronics1 yes I think its the challenge that attracts me to it :)
I believe 2 GB is the partition size limit for MS-DOS 6.
This is correct. That's the 16-bit addressable limit.
The BIOS Parameter Block has a bit field with an option to define the cluster size, as a multiple of the sector size. The maximum cluster size is 32K - probably something to do with 64K being a full segment or the 16-bit unsigned int size and making it difficult to support without overflowing. IIRC, the MS FAT32 specifications document addresses this, but I don’t remember what the exact justification was.
You CAN actually force this, by setting the BPB value one higher, and some FAT implementations will be OK with it. I have a C library I’ve been chipping away at for a few years, just for fun, and it can hang with it (it’s built for FAT-32 sizes.) But DOS won’t.
Anyway, at a cluster size of 32K, and on FAT-16 where the FAT can only hold just under 64K cluster entries (from memory 65532?), that works out to 2GB.
I would be really excited to see you do the SnarkBarker MCA project card for this machine. A Sound Blaster 1.5 alike with a new PCB project would be cool to see built. I have a NCR 386/MC-20 system with the 486 card for it that is Micro Channel. Sadly, NCR doesn't have the images for the disks any more and the SCSI drive in it died. I tried using a Master Disk for a PS/2 but it did not work. I have been on the look out for the NCR master diskette ever since I got the machine. I hope to find a disk image or a real disk some day.
I think the SnarkBarker is better suited for my 486 PS/2s. At the moment I'm considering the Plaid Bib for this "early DOS gamer" 286. Oh, non-IBM MCA machine : ) That is cool, good luck finding the disk image
If you still need to paint your ps/2 cover try checking if local hardware or paint stores can do colour matching. You typically just take in a piece of the same material with the correct colour and they'll use their camera thing to get the right colour for you.
Yeah, I have checked but unfortunately, they have different color codes than the automotive stuff we need for our IBMs
FDISK only affects the partition table, so if you remove a partition and recreate a partition with the same "geometry", (almost) all the data will still be there.
Oh, that's new to me. Never had this happened before. The format command seems to have erased it properly though, Thanks
I seem to remember that DOS fdisk actually erases the first sector(s?) of the partition when you create it, to avoid leftovers causing problems. Maybe I’m mistaken, but that’s the trivia stuck in my head.
@@nickwallette6201 I really don't know what happened there, I have installed DOS so many times and never had the installer get confused in this way
@@nickwallette6201 You're more or less right, but there is a second copy of FAT.
@@TzOk I’m aware, but the first sector is where the BIOS Parameter Block is stored. Without that, the rest of the volume is indecipherable. You wouldn’t know where the FATs were or how long they are. You could potentially recover with judicious use of heuristics and educated guesses, but DOS doesn’t do that.
Yeah, those ESDI drives were notoriously unreliable. The heads tended to get stuck, and you could unstick them by lifting the front of the machine a few cm off the desk and dropping it a couple of times. Until the heads snap off the arms. Which is why I'm looking at trying to replace it with a BlueSCSI.
Can you set the clock time using the MS-DOS time command?
For the paint, your best bet would be to get it colour matched. All of my model 50s have rust on the covers, so I'll also need to get mine painted. I have to figure out how to treat the rust first though, otherwise it will just continue to rust under the paint.
Turns out I was wrong in my previous comment about the model of monitor that's currently on my healing bench, it's an 8518, not an 8514 like I thought. I incorrectly assumed that the 14 in 8514 was the size, but that was wrong. My working 8513 is the 12" model, and my 8518 is the 14" model. It's a much nicer monitor than the 8513, so I would like to get it working someday.
I think you'll also need a memory expansion card if you want to run more complex software like windows. From memory (pun intended), the memory isn't compatible with standard 30 pin SIMMs, so you can't just replace them to upgrade the memory. Although your memory modules do look different to the ones in my model 50s, so I may be wrong in your case.
Anyway, I'm glad you've got this machine working as well as it is. Can't wait to see your next video on this machine!
That is exactly what happened to my ESDI. The heads got stuck midways on the platter and started to grind away the surface :/
Yes, the clock was set in DOS and I got some help to find the clock settings in 'BIOS' too. I think it was the second menu option. Set features?
I actually really like my 8513 :) It's tiny and low res but there is something with the colors that makes my DOS games look amazing. I think it might just be that it's adjusted to slightly warmer colors than my 8518.
Perhaps you have a 50Z? They have a different MOBO. I think there is a hack to make regular SIMMs work in a PS/2. I need to do some reading.
Thanks :)
Thanks for this great video!
One thing that I really wonder: Those hard drives can die any day now, so why don't you use something like SCSI2SD or a similar solution?
I'm old-school, I love my mechanical hard drives : ) I'll use them as long as they last, thanks
Gotta do a reboot after fdisk after changing partitions for it to properly work.
I might have missed this, I thought I had done a reboot
@@Epictronics1 it might have been edited out but it doesn't look like it in the video, hence my comment, but that's what the problem appears to be, I guess you can check the raw footage if you still have it
Wait - was there ever a version of fdisk that would let you exit without rebooting if you had made a change? I thought that was obligatory.
@@nickwallette6201 pretty sure the one in dos 6.22 just tells you to reboot but doesn't actually do so.
DOS 6?? This is solidly a DOS 4.0 machine. C’mon, you can handle it! :-D
Haha, It's actually an IBM PC DOS 3.30 machine. But I have enough hassle with Edlin on my XT machines already :)
I was just watching season 5 of Computer Chronicles, circa 1988. They announced the release of DOS 4, and what would become the PS/2 Model 30 286, in separate Random Access news segments.
But yes, yours (the Model 50) definitely would’ve shipped with 3.x. :-)
Great restoration!!!
Aside all, did u tried those SP2 DreamBlaster parallel port Midi card?
You just added a 6th option to my list : ) Thanks
A unicorn 286 machine? Hopefully its an IBM 5162.
There is only one way to find out : )
I'm thinking of a solution for the sound, TexElec has a couple of options available. Also, I know that it's not a mechanical drive solution, but what about a BlueSCSI? The BlueSCSI is constantly being updated for all kinds of machines, iirc.
You're right, BlueSCSI is probably the way to go here... but I love my mechanical hard drives : ) At the moment I'm considering the Plaid Bib
Hello, I have an IBM personal system /2 model 55 SX, but the floppy drive seems to work fine, but it stays with the light on and can't read the disk, although the motor turns and the head also moves when it starts up Reader, it could be a controller chip that is broken, I've seen a video where you change it and it works but this model is different and I don't see it, could you help me?
The FDD controller chip rarely brakes so I would first check all the typical faults on the FDD even in this case. Replace the three caps, clean the heads and check head alignment. If that doesn't work, google the numbers on the chips you have on the board until you find the FDD controller. good luck with the project
@@Epictronics1 thanks dude, i hope i can revive at least the floppy drive, the hard drive sounds pretty good but it won't start, it goes directly to basic, i was looking to load programs via cassette tape in basic at least to use it, but i'll give it another chance to the floppy drive, I tried to make the Mod with 2 new floppy drives but they both died in the attempt, I'll give the original another chance to see if there's any luck, thanks, great videos and great channel!
@@elrincondellobezno6726 Thank you:) You're in luck, I'm recording a PS/2 video this week and it has a bad diskette drive!
@@Epictronics1 awesome!, good job!!
Ral 9002 i think i read some time ago on vogons that was a good match for those old machines
Great, I'll try it out, thanks
Ral 9003 also seems a good candidate
@@Aisflou I had a look at a RAL chart. They look pretty good, I'll give them a try, they seem to be available online
The motherboard in my Model 50 is much different than the one you are showing. However, mine is a Model 50 Z. I assume yours is not a "Z"?
Correct. The 50Z was a newer version IIRC
I'm not sure where you're located, but most paint retailers and some auto parts places can scan the colour for you and replicate it.
yeah, there is equipment to 'read' colors but I think it might be more expensive than a new case : )
@@Epictronics1 that service is free at home depot here in the usa, so more than likely you can find someone to match it for you for free.
@@bgibson9060 Yes, I have the same service locally. However, If I want a 2 component spray paint I think it's a bit trickier
if i could remember i would have find it somehow
i remember there 1gb ssd for old apple only run on ps2 slot which you using
There is something called BlueSCSI but I have another idea for this project :)
@@Epictronics1 oh neat i just stuck at home because it raining all 2 weeks and cant go in shed get old pc out box and i will try when there no storm rolling in (have drag everything out get to it)
Your mic appears to have picked up quite a bit of hiss
Thanks for the feedback. I'll check with my headphones
having bowels hanging outside of the case is feeling rather gutted, not nice
if you record high fps video footage, then you can sync the screen video manually, or, you could directly capture the screen from the video connector, or take the sync signal from the video connector
@@gsestream Manually? like in software? I can match my camera settings for 50 or 60 but apparently, this display is running at 70. Ideally, there would be a product with VGA connectors at both ends to put between the PC and CRT, and that would lower the refresh rate to 60. That would be the perfect product for vintage CRT recording
@@Epictronics1 think like screen tearing sync prevention but for camera, kinda variable refresh rate, or auto-frame tune (detect when a video frame has been completed, or you have the screen signal itself) in a video capture, but if you have a camera that can take say 300fps+ video