Sone stuff in the various chapters here... https://eprm.ardent-tool.com/eprm/f4.htm

A warning about that Sharp PC4500... it might become your favorite text adventure / WP 5.1 machine.

Here is the Maintenance manual for Model 2155 if you did not find it yet. http://ps-2.kev009.com/pccbbs/aptiva/63g2028.pdf
There is quite a bit of info at http://ps-2.kev009.com like here: http://ps-2.kev009.com/pcpartnerinfo/ctstips/326_2.htm but cannot find model sm1

That is my problem, I have found a 2155-nm1 but not the 2155-sm1, not sure if they are closely related. I am trying to tell from the picture if this thing has 30-pin or 72-pin sims, there are only two memory slots and they kinda look too long for 30-pin (I cannot zoom into the picture close enough to tell though). I am guessing this machine is from 94 as the sound blaster awe 32 was not introduced until 94. I have a 486dx2 66 overdrive with the 169 pins, that extra pin for the match coprocessor socket.

There has been a change of plans, my son is traveling to the area and has agreed to pick them up and bring them to me, so will get this sometime this weekend or early next week. The only problem with computer that the person has told me is that the front plastic cover is disintegrating, so might be working with machine without the front cover, oh well.

scottie4442 wrote on 2021-11-09, 19:20:

That is my problem, I have found a 2155-nm1 but not the 2155-sm1, not sure if they are closely related. I am trying to tell from the picture if this thing has 30-pin or 72-pin sims, there are only two memory slots and they kinda look too long for 30-pin (I cannot zoom into the picture close enough to tell though). I am guessing this machine is from 94 as the sound blaster awe 32 was not introduced until 94. I have a 486dx2 66 overdrive with the 169 pins, that extra pin for the match coprocessor socket.

There has been a change of plans, my son is traveling to the area and has agreed to pick them up and bring them to me, so will get this sometime this weekend or early next week. The only problem with computer that the person has told me is that the front plastic cover is disintegrating, so might be working with machine without the front cover, oh well.

Can find no reference to the SM1 model online, except this page on video RAM - http://ps-2.kev009.com/pcpartnerinfo/ctstips/8466.htm

Given that the NM1 was one of the last 2155 models released (around Spring 94) and was also around the time of the transition between PS/1 & Aptiva, I'd guess the SM1 is a minor package variant of the NM1. That being the case, the NM1 memory is covered by this quote...

"Regular system memory is upgraded with 36-bit or 32-bit (parity or non-parity) industry standard 70ns 72-pin SIMM chips. If the machine has 2 SIMM sockets, it can handle up to a 32MB SIMM in each socket. If it has 4 SIMM sockets, it can handle up to a 16MB SIMM in each socket."

http://ps-2.kev009.com/pcpartnerinfo/ctstips/8642.htm

Very few systems of that vintage had 30 pin simms

That “line” was available as a 386sx, 486sx,486dx and 486dx2 so it spanned a wide subset.

I would almost guarantee anything “new enough” to sport an awe32 will have 72pin simms.

PC Hoarder Patrol wrote on 2021-11-09, 23:54:

Can find no reference to the SM1 model online, except this page on video RAM - http://ps-2.kev009.com/pcpartnerinfo/ctstips/8466.htm
Given that the NM1 was one of the last 2155 models released (around Spring 94) and was also around the time of the transition between PS/1 & Aptiva, I'd guess the SM1 is a minor package variant of the NM1. That being the case, the NM1 memory is covered by this quote...

Good find ! That is what I was thinking too: Might have been a limited variant of the NM1 so not much documentation.

rmay635703 wrote on 2021-11-09, 23:55:

Very few systems of that vintage had 30 pin simms
That “line” was available as a 386sx, 486sx,486dx and 486dx2 so it spanned a wide subset.
I would almost guarantee anything “new enough” to sport an awe32 will have 72pin simms.

Ahh not neccesarily so. The NM1 came with Sb16, my guess is that the Awe32 was added later replacing the original SB16.
Also the PS1 33Mhz DX had 30pin simms in many PS1 models.
You can check here: http://ps-2.kev009.com/pcpartnerinfo/ctstips/3ab6.htm

Really would like to see some good pictures !

I have several IBM PS/1 computers. There were about 10 or more models thru out the years from 1993 thru 94.
It all depended on what store you purchased the computer from.
It was a marketing scheme by IBM so they are all slightly different.
Mainly different motherboards.

But NONE had an Onboard AWE64 or any type on onboard audio.

Some IBM PS/1 computer from 1993 in particular the IBM PS/1 Multimedia edition came with a CDROM and Sound card.
They came with a 2x Panasonic / Matsushita CDROM and Sound Blaster Pro 2.0 or CT2950 or CT4770

The ones I have came with the CT2950.

READ my Posts for more info.
1) IBM PS/1 Multimedia ( max restore ).
2) IBM PS/1 Consultant 1993 with Sound blaster.
3) IBM PS/1 Multimedia ( max restore ).

As for RAM and Cache and CPU upgrade Dont bother.

1) RAM Upgrade ?..16mb of FPM RAM for DOS/Win3x is enough. Supports up to 32mb RAM.
2) Motherboard Cache upgrade?.. Supports up to 256kb of cache. But will only give a 3% performance boost over stock 64kb.
3) CPU Upgrade ?..With the Right Intel Overdrive CPU you can upgrade these to 486dx2-33 thru 486dx4-100 or add an Intel Pentium Overdrive 83mhz CPU.

But then It will NOT be a 486 computer anymore. Since you said you already have Pentium computers.
I would just keep it a 486. A 486dx2-50 thru 486dx4-100 is good enough for a 486 computer.
Either way it will NOT compare to a Pentium computer. The Pentium computer is actually best for playing DOS games for Best performance.

I would however definitely use the original IBM install. I use the 1994 Multimedia image with built in support and programs for Sound Blaster.
You can download it here.
https://ps1stuff.wordpress.com/download/downl … -for-type-2133/

Just download on your modem PC and extract in a folder.
Burn contents to CD-R
Get a DOS 5.0 bootable floppy with CDROM support
https://www.allbootdisks.com/download/dos.html

On your 486 computer boot off the Floppy diskette.
Partition and Format your hard drive

Copy contents from CD-R to Harddrive
# xcopy /e /s R:*.* c:\

Sys the C: drive
# Sys C:

ok, fingured this out. My brothertok this picture at a bad angle so I was seeing the installed awe32 CARD that was installed in a pci slot, could not see the motherboard at all. I am supposed to get this computer the end of the week so will post futhur updates then. I do know that the front plastic bezel is disentigrated and he removed it, anyone have an idea where I can get a new(er) one?

I finally got this computer an tore it down for a good cleaning. the last person had added a 468dx2-50 but it had come out of the socket and broke several pins (replaced it with a 486dx2-66 but still only shows as 486dx-50 though). the cdrom is not the right one for the awe32 interface and the hard drive was "pinballing" (making weird noises). I replaced the hard drive with a 20gb and planned on putting 4 2gb partitions, but it only let me put one 503mb partition on the hard drive, old ide format on the controller. I am waiting on a new eide controller and will plug the hard drive and cdrom into that. I also have memory coming in, plan to try to upgrade to 64mb ram, I have 16mb in it already. I did hwinfo and found out that I have 1mb of video memory to my suprsise. I do not have any cache chips or sockets on the motherboard, not sure if I want to mess with this. Oh it does only have 2 simms sockets, not sure how to identify the motherboard model though. Thanks for all the suggestions and help here.

change the last message, the cd-rom is the right one for the ide interface, just was not setting it up right, I posted in Marvin/sound about this. I got it working, but had to change the cd-rom out as the old one only read published cd-roms, the new one reads published cd-roms and cd-rs. I am going to get an isa ide controller so that I can access the full 2gb partitions of ms-dos 6.22, right now it only lets me have one partition at 503mb. will post about this later. Tried to install 2 32mb simms and it would not take them, I have a 16mb and an 8mb simms in this unit and it sees the 24mb fine. On an unusual note it has a reval FM rasio card in it (not sure if that is how you spell the company name). and another card that looks like another 25 pin serial but it does not show up in hwinfo as a serial, this system only shows 2 serial ports both on the motherboard, tried to find any identification on this card and there is nothing except a sticker on the mounting plate that says scanner, I will probably remove it.

scottie4442 wrote on 2021-11-29, 21:59:

change the last message, the cd-rom is the right one for the ide interface, just was not setting it up right, I posted in Marvin/sound about this. I got it working, but had to change the cd-rom out as the old one only read published cd-roms, the new one reads published cd-roms and cd-rs. I am going to get an isa ide controller so that I can access the full 2gb partitions of ms-dos 6.22, right now it only lets me have one partition at 503mb. will post about this later. Tried to install 2 32mb simms and it would not take them, I have a 16mb and an 8mb simms in this unit and it sees the 24mb fine. On an unusual note it has a reval FM rasio card in it (not sure if that is how you spell the company name). and another card that looks like another 25 pin serial but it does not show up in hwinfo as a serial, this system only shows 2 serial ports both on the motherboard, tried to find any identification on this card and there is nothing except a sticker on the mounting plate that says scanner, I will probably remove it.

Now you have the system in hand maybe share a few pics inside & out...the 'serial' card may be a SCSI DB25 pin interface for the noted scanner & the Reveal (AIMS Lab?) FM radio card still has software available online if your interested.

ok, hadn't thought about a scsi card for the unknown one. I have seen the drivers for the reveal fm radio card, can I just plug the output of that card to the line in for the sound blaster? I will take some pictures of the machine, although the front bezel completely fell apart when my brother loaded it for me, so the machine looks really nice except for the front bezel, I have been looking around for a 2155 front bezel or case but no luck so far.