Doornkaat wrote on 2023-03-28, 09:49:

Ozzuneoj wrote on 2023-03-27, 18:21:

Someone on the PS/2 Google Group gave basic diagnostic steps of removing RAM, starting with a pair and going from there. This got me to try different sticks and sure enough, the ONE stick I had settled on using is the one that is not compatible with this system.

Doornkaat wrote on 2023-03-27, 14:16:

Did you try other known good RAM modules?

Just saying.🤷‍♂️😜

Yeah, you had mentioned RAM too, you're right, heh. Sorry.

I don't exactly have any known good SIMMs, because I haven't powered on any of my available 72pin systems in a while and my stockpile of RAM is basically untested.

It was unlikely that all four sticks it came with were bad, so I did test all of the sticks in the system individually, as mentioned, but the problem seemed to be that I just wasn't familiar with the startup process of these things and they will look dead unless you wait 20-30 seconds. I waited several minutes longer on the one that actually didn't work. If I'd simply waited that long when testing one of the other sticks (the first step I did after swapping the battery, before even posting here) it would have been working.

I'm curious to know what it will do if I install some random untested memory from my stockpile.

It'll probably work fine. :Rofl:

luckybob wrote on 2023-03-28, 02:47:

oh I've had a rough weekend, I really needed that laugh. Glad to hear you got it going.

Well... Sometimes miracles happen 😜.

Ozzuneoj wrote on 2023-03-28, 13:53:

I'm curious to know what it will do if I install some random untested memory from my stockpile.

It'll probably work fine. :Rofl:

At least my PS/2, and I think most of them do, require memory with parity. Of course regular FPM with parity won’t work. Also 60ns doesn’t work. However, many regular 60ns FPM memory sticks with parity and can be modded relatively easy to work in PS/2 systems.

So chances that your random 72-pin SIMM works in your model 90 are slim, unless you happen to have some IBM FRU stuff in your pile 🤣

Ozzuneoj wrote on 2023-03-28, 13:53:

I'm curious to know what it will do if I install some random untested memory from my stockpile.

It'll probably work fine. :Rofl:

Spiteful memories!😄

CharlieFoxtrot wrote on 2023-03-28, 14:44:

Ozzuneoj wrote on 2023-03-28, 13:53:

I'm curious to know what it will do if I install some random untested memory from my stockpile.

It'll probably work fine. :Rofl:

At least my PS/2, and I think most of them do, require memory with parity. Of course regular FPM with parity won’t work. Also 60ns doesn’t work. However, many regular 60ns FPM memory sticks with parity and can be modded relatively easy to work in PS/2 systems.

So chances that your random 72-pin SIMM works in your model 90 are slim, unless you happen to have some IBM FRU stuff in your pile 🤣

I'm not too familiar with parity memory. Do 12 chip SIMMs generally have parity? The parity SIMMs I remember seeing had 9 chips. The ones in this PS/2 were are all 12 chip.

I have quite a bit of memory. I just might have some that goes in this thing. 🤣

Doornkaat wrote on 2023-03-28, 15:00:

Ozzuneoj wrote on 2023-03-28, 13:53:

I'm curious to know what it will do if I install some random untested memory from my stockpile.

It'll probably work fine. :Rofl:

Spiteful memories!😄

Indeed! Sometimes it seems like computer components are out to make me look even dumber than I am. Like kicking a guy when he's down. 🤣

hyoenmadan wrote on 2023-03-28, 14:21:

luckybob wrote on 2023-03-28, 02:47:

oh I've had a rough weekend, I really needed that laugh. Glad to hear you got it going.

Well... Sometimes miracles happen 😜.

Just saying, but I managed to find two Paradise Tasmania 3D cards within 30 minutes of each other a couple months back, and one was sealed in box and was dirt cheap... apparently these are like the 4th and 5th cards to be in anyone's hands, so yeah, some times this stuff just pops up. If you happen to be the one with your mouse hovering over the "Buy it Now" button, then your chances of getting unobtainium cards suddenly go up dramatically. 😁

The requirements for ram change with the cpu complex. The pentium cpu boards pretty much require 36 x 9 style "ecc" simms.

If I can find someone who can reverse engineer a 32mb simm to recreate them, I'd love to get in contact with that person.

Ozzuneoj wrote on 2023-03-28, 15:40:

I'm not too familiar with parity memory. Do 12 chip SIMMs generally have parity? The parity SIMMs I remember seeing had 9 chips. The ones in this PS/2 were are all 12 chip.

I have quite a bit of memory. I just might have some that goes in this thing. 🤣

There might be better memory experts than me, but in my understanding 12 chip memory is usually parity, but not always. I have 12 chip sticks in my model 35. Uneven number of chips also means parity, so 9 chips is yes.

But if they are standard parity simms, they won’t work on your PS/2 out of the box. If they are for PS/2, you are good to go. Ardent Tool has memory compatibility matrix to help with finding compatible FRU RAM.

Okay, I have tested a whole bunch of memory and here are my findings.

The only SIMMs that work have 12 or 24 chips. Some threw me off because they had a row of 10 on each side and one row of 4 chips in another orientation on one side... but it all works out to 24 chips regardless. Absolutely none of the memory sticks I tried with anything but 12 or 24 chips worked in this system.

Many of the sticks with 12 or 24 chips do not work for some other reason, and the vast majority of them were 16MB SIMMs. I have read that this model should support 64MB of RAM, but none of the 16MB SIMMs I tried worked at all. Most of them immediately gave a 0002151E error, which I can't find anything about specifically. One page says 2151 is "Lost data set ready during data wrap" ... whatever that means. 😮 I have some brand new, sealed pairs of 16MB FP SIMMs I bought for use in AWE32 cards 6-7 years ago, and that also did not work. As far as I can tell, all of the ones that did not work have chips on them that contain "17400" in them.

... oh duh! I guess it probably just can't handle 16MB SIMMs at all. To get 64MB you would just populate both of the RAM card slots, so you'd have 8 SIMMs installed... 8MB each. I only have one RAM card. DERP! That makes more sense. Anyway, this big revelation of mine is probably common knowledge in PS/2 land, but it feels good to have confirmation through testing.

I did find several 4MB sticks that worked. I was very happy to see at least one set of 2x8MB sticks worked, so I should be able to get this system to 28MB at least. I would imagine that Windows 95 runs a tiny bit better with 28MB versus 16MB, especially with a slow old 140MB hard drive. It does irk me just a tiny bit that I won't be able to get it to 32MB since I can't seem to find any other 8MB SIMMs with the correct configuration... but I really doubt it will matter much.

Also, some that worked were 60ns, and some were 70ns.

This about sums up my findings. It was definitely not an issue of bad RAM. That one stick was just incompatible. Several of the ones I installed would give errors (no memory at all), but almost all of the ones that had 8, 9 or 16 chips simply made the system hang at the blinking cursor, which is what I was originally dealing with. I'm guessing someone threw that RAM stick in there right before it was packed away for 15 years. Oh well. It forced me into my first PS/2 learning experience. 😜

EDIT: Whelp... it doesn't like 28MB (8+8+8+4). It works with 24MB (8+8+8) but if I add another 4MB stick it only detects 12MB... or sometimes it will hang before the memory check, even those all of those sticks work individually. It may be possible to find the right combination but it's proving to be a bit of a pain.

... so, 24MB it is for the 'ol PS/2!

EDIT2: Okay... what gives? Windows 95 is reporting 16MB of RAM even though the BIOS detects 24MB. I am using 8+8+4+4 SIMMs.

Is this a PS/2 issue or a Windows 95 issue? I have, admittedly, not dabbled with 95 much over the years.

I have a vauge memory that win95's integrated memory manager doesnt like some MCA systems. there is a fixed file out there, but I;m not at my desktop to look it up.

luckybob wrote on 2023-03-29, 02:25:

I have a vauge memory that win95's integrated memory manager doesnt like some MCA systems. there is a fixed file out there, but I;m not at my desktop to look it up.

Your vague memory of vague memory managers was correct!
https://ardent-tool.com/utils/himem.html

Haven't tried it yet, but I'll download this updated HIMEM.SYS later and I'm sure that'll fix it (with the /P switch if course).

Sounds right, I had a lonely brain cell going "It's that 16 meg fing innit?" "What 16MB thing?" "You know, the thing, with the 16 meg" "Yes the thing with the 16 megabytes, what about it? What do I look for?" "Guys, guys, wake up, tell him about the fing with the 16Mb, I was only the bookmark .. *crickets* " ...

BitWrangler wrote on 2023-03-29, 14:46:

Sounds right, I had a lonely brain cell going "It's that 16 meg fing innit?" "What 16MB thing?" "You know, the thing, with the 16 meg" "Yes the thing with the 16 megabytes, what about it? What do I look for?" "Guys, guys, wake up, tell him about the fing with the 16Mb, I was only the bookmark .. *crickets* " ...

🤣

You have a whole dysfunctional team of British PC repair techs in your brain too, eh?

Anyway, I downloaded the HIMEM update aaaannndd....... the floppy drive in the PS/2 won't read. 😭

Others have mentioned the drive will probably have bad caps. Hopefully it's just dirty, but... oy. I just want to close the machine up and get back to what I was doing before my friend brought this over. 🤣

It has a CD-ROM drive but... can I really get myself to burn a write-once CD with a 28KB zip file on it???

EDIT: YES! It was just dirty. I put a cleaning disk in it, accessed it a couple times and now it's reading fine. WHEW.

EDIT2: Success! The PS/2 Model 90 now has 24MB of RAM. 😀

Now that I'm actually using the system I'm noticing that the floppy and CD-ROM drive are just kind of loosely fit into the machine, with a clear plastic clip\bracket on the floppy and two black plastic rails (that don't snap in place) on the CD-ROM. Since the CD-ROM was added on later, it doesn't have a bezel that matches this system so there is a gap around it. I found this page mentions a bezel kit (at the bottom) and I found the kit here. Seems like a nice option if I ever want to clean up the look of the machine. I kind of want to wait until I know if I need any other parts though. And at this point I don't even know if that site is still operating. I have looked around and haven't been able to find a 3D printable model of the awesome looking angular CD-ROM cover shown on the Ardent Tool page. I would much rather use one of those, and I believe this is an original PS/2 CD-ROM drive so it should fit. It actually came with a caddy in it. 😀

The drive is a Toshiba XM-3301BME. No mention of IBM on it, but it does have the blue eject button and volume wheel.

yea. I was going to post here how I had 3d-printed teh bezel already...

https://www.thingiverse.com/thing:5382210

its for the 85/95.

The caps in the floppy drive are likely near death. replacing them now before they blow their spooge all over the place is highly recommended.

luckybob wrote on 2023-03-29, 18:53:

yea. I was going to post here how I had 3d-printed teh bezel already... […]
Show full quote

yea. I was going to post here how I had 3d-printed teh bezel already...

https://www.thingiverse.com/thing:5382210

its for the 85/95.

The caps in the floppy drive are likely near death. replacing them now before they blow their spooge all over the place is highly recommended.

Thanks, if I can find the right color filament I may have a buddy of mine make one, though I would really prefer the angled type that matches the shape of the machine. They seem ridiculously rare so I don't think anyone has been able to get one and make a 3D model of it for printing. What color and type of filament did you use for this? And is it likely to fit the Model 90 without issues?

Thanks for the capacitor tip. I don't like leaky cap spooge. 🙁

Are they surface mount caps?

as i understand it, its just 3 bog-standard surface mount caps. nothing special. there are pics on the internet and on other vogons threads.

The bezel i linked is for the model 85/95. the tower.

I did not find a 3D print bezel for the model 90. If you find one, i'll be happy to give it a test for you.

luckybob wrote on 2023-03-29, 23:37:

as i understand it, its just 3 bog-standard surface mount caps. nothing special. there are pics on the internet and on other vogons threads.

The bezel i linked is for the model 85/95. the tower.

I did not find a 3D print bezel for the model 90. If you find one, i'll be happy to give it a test for you.

Oh right, I didn't realize those were towers. Doh.

I see now that another bezel I found is also for PS/2 towers:

https://www.thingiverse.com/thing:4572066

I would definitely buy one of the angled ones if they existed. Like the top one in this picture:
https://ardent-tool.com/90/Bay_B_Bezels_CDROM.jpg

The system in this video appears to have the same CD-ROM as mine, with that bezel, so it would fit.
https://www.youtube.com/watch?v=Bhvfa3zRaGs

If anyone has one, they could make a lot of friends if they somehow got it 3D scanned and converted to a proper 3D print model. 😀

Ozzuneoj wrote on 2023-03-29, 19:46:

Are they surface mount caps?

There usually can be several different type of drives and from different manufacturers in these systems. AFAIK a FRU number can have drives from different manufacturers, so FRU isn't necessary unique in this sense. Because drive models can be different, it also means that the amount and specs of capacitors can vary too although what I've seen, yes, they use SMD. Ardent tool has a list of models and drives (as well other useful info), although I can't say if the list is complete:
https://ardent-tool.com/floppy/floppy.html#Floppy_List

For example, my 35SX has 1.44MB Alps drive with 9 caps. To change all caps in this drive, you need to remove the control board, because control board caps are on the top side, so you can't access those caps with drive fully assembled. Another thing to note is that the three caps in the motor board and closest to the floppy slot are of bi-polar type. Here is my drive disassembled, but before the recapping. Pretty much all caps had been leaking, although it wasn't a huge mess and there was no corrosion on the boards, at least yet:

Control PCB:

Motor PCB:

My drive wasn't reading disks anymore before changing the caps and you can consider yourself lucky in this sense. However, what I've read about these capacitor issues, people were recapping these drives already in the early 2000s, so it could be possible that yours has already got new capacitors at some point.

IBM 90 XP is a IML machine that stores bios firmware on hard drive. You need to initialize the hard drive then insert the IML firmware then proceed with partition and formatting as instructed in the read me.

I can send you my 4MB memory modules enough for 16MB and some left over for your 90 XP as they are propriety and is no use for me. They are correct part.

I had 90 XP once. Unfortunately.

Cheers,

pentiumspeed wrote on 2023-03-30, 20:04:

IBM 90 XP is a IML machine that stores bios firmware on hard drive. You need to initialize the hard drive then insert the IML […]
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IBM 90 XP is a IML machine that stores bios firmware on hard drive. You need to initialize the hard drive then insert the IML firmware then proceed with partition and formatting as instructed in the read me.

I can send you my 4MB memory modules enough for 16MB and some left over for your 90 XP as they are propriety and is no use for me. They are correct part.

I had 90 XP once. Unfortunately.

Cheers,

This has all been taken care of throughout the thread and the machine is working fine with proper RAM in it, but thank you anyway.

If I ever found another RAM card to install the SIMMs onto I would probably use that RAM, but as it is I would have no way to use it as I have 24MB installed now.