After posting this, I decided to remove the mouse driver from autoexec.bat and then used the keyboard to uninstall the mouse from the Device Manager in Windows. Upon restarting and logging into Windows, I wanted to test whether moving the mouse would still lock the keyboard. I expected it wouldn't, but to my surprise, the mouse was functioning again, and there was no keyboard lockup. I'm utterly perplexed about what happened. I'm still uncertain whether the video memory upgrade caused this issue or if it was merely a random coincidence. I'm contemplating reinstalling the video memory, but I hope someone can confirm if the memory I posted a picture of earlier is compatible. In hindsight, I should have used keyboard commands to check dxdiag while the memory was still installed.

I have the same system but in tower form: 466DX2/Tp and also had a REALLY hard time finding a HDD that would work with the system.
Like you I was getting the controller error messages that prevented booting. Updated to latest BIOS as well, even tried ldjt81a.exe that was an unrelated languages update but it did not help.
Tried many IDE HDDs I had and in the end I found a single 10GB Seagate drive that would not cause the controller to fail and also found a 4GB CF that would also allow boot.
I have no idea why this particular HDD works - it is one left from upgrading the og XBOX and I have a bunch of them that according to their labels all are the same model/fw .
Ofcourse I had to use EZ-disk to utilize the full size of the drives.

I would be very interested to find out what this super-weirdness with the onboard hdd controller is, it almost makes no sense.

Also upgraded the VRAM but I just "borrowed" it from a PCI s3 card , it just worked.

It does seem odd, doesn’t it? I can picture a bunch of frustrated customers back in the late ‘90s, stuck with systems they couldn’t upgrade to bigger drives. I recall around 1997 or so, I helped upgrade about two dozen Compaqs using ez-drive and a Norton Ghost image to make the process smoother.

I don’t have enough spare HDDs lying around to test this out until I track more down, but mTCP netdrive has taken care of the storage issue. And honestly, how much data do you really need for these old 486 machines anyway?

I’m eager to give the VRAM upgrade another shot, but I’m feeling a bit cautious about trying again.

I tried one of those 5x86 CPU adapters in my IBM PS/1.
It worked but from what I remember the CPU cache gets disables or something like that.
But it does work
You need to set your motherboard CPU jumpers for 33mhz CPU.

Intel486dx33 wrote on 2025-03-18, 23:48:

I tried one of those 5x86 CPU adapters in my IBM PS/1. It worked but from what I remember the CPU cache gets disables or somethi […]
Show full quote

I tried one of those 5x86 CPU adapters in my IBM PS/1.
It worked but from what I remember the CPU cache gets disables or something like that.
But it does work
You need to set your motherboard CPU jumpers for 33mhz CPU.

This IBM mainboard allows me to configure the FSB to 25MHz, 33MHz, 40MHz, or 50MHz. I've experimented with various settings, and these options are listed on the back of the CPU blaster I own.(recreated image below) It uses 4 pins, and you adjust the jumper based on the desired setting, but I'm uncertain whether the issue lies with the CPU I used or the blaster itself. I’ve ordered a 133MHz AMD 5x86 that’s supposedly tested and functional, so I’ll be trying that out soon to see how it performs.

Save your time and money.
Use an Intel overdrive 486dx4-100 or Intel Pentium overdrive 83mhz.

Intel486dx33 wrote on 2025-03-19, 02:23:

Save your time and money.
Use an Intel overdrive 486dx4-100 or Intel Pentium overdrive 83mhz.

That would be ideal, but I haven’t managed to find one at a reasonable price yet, so I’m currently using an Intel Pentium Overdrive 63MHz. It’s capable of running at 83MHz, but it’s not very stable—sometimes it works, sometimes it doesn’t. This is quite a bit faster than the DX2/66 that I replaced it with.

My two cents…

I have an IBM PC330 DX2 that i think share the same motherboard. After some test i found that the maximum you can install is a 4GB CF… but not all. I have 10 Sandisk 4GB differrnt series but all marked at 4GB. Probably some models are lettle less than 4096kb and work with no problem… you must find the 4GB cf tryng…

About cpu, i have a POD83mhz that work.. but with weird settimg (now i can’t remember wich settimgs but not the marked on the board) a cyrix 5x86 that work and a AMD 5x86 p75 (or something similar) that refuse to work, no matter the settings.

Note that a regula DX4 100 work perfect, add a fan and probably will work for long time. My POD83 work at 100mhz but i have just tries some doom and quake run and set again to 83mhz. This cpu is too rare to find and i not want to fried it.

Intel486dx33 wrote on 2025-03-18, 23:48:

I tried one of those 5x86 CPU adapters in my IBM PS/1. It worked but from what I remember the CPU cache gets disables or somethi […]
Show full quote

I tried one of those 5x86 CPU adapters in my IBM PS/1.
It worked but from what I remember the CPU cache gets disables or something like that.
But it does work
You need to set your motherboard CPU jumpers for 33mhz CPU.

That may be due to the same bug that myself and epictronics experienced when we installed ODP 486DX4-100's in ours, which is fixed with the "TOM" BIOS.

AlessandroB wrote on 2025-03-19, 21:21:

My two cents… […]
Show full quote

My two cents…

I have an IBM PC330 DX2 that i think share the same motherboard. After some test i found that the maximum you can install is a 4GB CF… but not all. I have 10 Sandisk 4GB differrnt series but all marked at 4GB. Probably some models are lettle less than 4096kb and work with no problem… you must find the 4GB cf tryng…

About cpu, i have a POD83mhz that work.. but with weird settimg (now i can’t remember wich settimgs but not the marked on the board) a cyrix 5x86 that work and a AMD 5x86 p75 (or something similar) that refuse to work, no matter the settings.

Note that a regula DX4 100 work perfect, add a fan and probably will work for long time. My POD83 work at 100mhz but i have just tries some doom and quake run and set again to 83mhz. This cpu is too rare to find and i not want to fried it.

Hey, thanks for chiming in with your two cents—definitely appreciated! It’s cool to hear you’ve got a PC330 DX2 that might share the same board as my ValuePoint 466DX2/SP. The CF card limit is good to know—I’ll keep an eye out for the “right” 4GB SanDisk model.

On the CPU front, that’s interesting about the POD83MHz working with weird settings, since that is the same pattern with the POD63MHz. I might dig into that a bit more if I can track one down, though I hear you on not wanting to fry it—those are unicorns these days! I’ve been tempted to try a Cyrix 5x86, my next try is a AMD 5x86-P75, so it’s helpful to know the AMD gave you trouble. Maybe it’s pickier with this board than I thought. A DX4-100 with a fan does sound like a solid, safe bet though—I’ll probably start with the P75 and see how it holds up.

Thanks again for the insights! I’ll report back if I make any headway with the CF or CPU upgrades.

Cheers!

OVERK|LL wrote on 2025-03-20, 13:15:

That may be due to the same bug that myself and epictronics experienced when we installed ODP 486DX4-100's in ours, which is fixed with the "TOM" BIOS.

Hey, your mention of the TOM BIOS has me seriously intrigued—I’ve got to hear more about this. What was the deal with that ODP 486DX4-100 bug you and epictronics stumbled across? What kind of mess did it cause, and how did this BIOS sort it out? Although I doubt the TOM BIOS would play nice with this Valuepoint, I’m still super curious to hear the full story.

Demo wrote on 2025-03-20, 13:31:

OVERK|LL wrote on 2025-03-20, 13:15:

That may be due to the same bug that myself and epictronics experienced when we installed ODP 486DX4-100's in ours, which is fixed with the "TOM" BIOS.

Hey, your mention of the TOM BIOS has me seriously intrigued—I’ve got to hear more about this. What was the deal with that ODP 486DX4-100 bug you and epictronics stumbled across? What kind of mess did it cause, and how did this BIOS sort it out? Although I doubt the TOM BIOS would play nice with this Valuepoint, I’m still super curious to hear the full story.

I take zero credit for the discovery, as I was pointed to one of epictronics' Youtube videos when I was trying to hotrod my PS/1. My original plans were pretty tame: ODP 486DX2-75, max out the RAM. However, a member who is on here and on another forum I'm on (rmay) shared the epictronics adventure, including the FSB mod (I have a 2133 w/25Mhz FSB), which I originally didn't want to do, since I've owned this computer since the mid 90's and was concerned about taking an iron to it, but eventually threw caution to the wind and did that too.

Anyway, long story short, epictronics discovered that when he put a DX4 ODP into the 169-pin copro/ODP socket on the 2133 that it "worked", but disables the L1 cache, and you can "enable" it, but it doesn't actually enable (and shows disabled when you go back into the BIOS), which of course neuters performance and makes it worse than with the SX25. Of course IBM didn't support the DX4 ODP's as an upgrade path, and this is likely the same bug we see manifesting with the 5x86 CPU's, which I believe epictronics has also tested.

So, Major Tom, from the PS/2 site, took the 2133 BIOS (same version mine shipped with) and modded it to eliminate this problem. It's available on the PS/1 Stuff page now:
https://ps1stuff.wordpress.com/download/downl … -for-type-2133/

Epictronics obtained a copy of this ROM from TOM (before it was available as a download), and boom, cache was back! Now, the cache in the BIOS shows 8kb, but the CPU has 16kb and when you run the benchmarks, it's obvious that you have 16kb, not 8, despite what the BIOS says. Just like the BIOS doesn't show you have a DX4 installed.

You want any more details, let me know 😀

OVERK|LL wrote on 2025-03-20, 13:15:

I take zero credit for the discovery, as I was pointed to one of epictronics' Youtube videos when I was trying to hotrod my PS/1 […]
Show full quote

I take zero credit for the discovery, as I was pointed to one of epictronics' Youtube videos when I was trying to hotrod my PS/1. My original plans were pretty tame: ODP 486DX2-75, max out the RAM. However, a member who is on here and on another forum I'm on (rmay) shared the epictronics adventure, including the FSB mod (I have a 2133 w/25Mhz FSB), which I originally didn't want to do, since I've owned this computer since the mid 90's and was concerned about taking an iron to it, but eventually threw caution to the wind and did that too.

Anyway, long story short, epictronics discovered that when he put a DX4 ODP into the 169-pin copro/ODP socket on the 2133 that it "worked", but disables the L1 cache, and you can "enable" it, but it doesn't actually enable (and shows disabled when you go back into the BIOS), which of course neuters performance and makes it worse than with the SX25. Of course IBM didn't support the DX4 ODP's as an upgrade path, and this is likely the same bug we see manifesting with the 5x86 CPU's, which I believe epictronics has also tested.

So, Major Tom, from the PS/2 site, took the 2133 BIOS (same version mine shipped with) and modded it to eliminate this problem. It's available on the PS/1 Stuff page now:
https://ps1stuff.wordpress.com/download/downl … -for-type-2133/

Epictronics obtained a copy of this ROM from TOM (before it was available as a download), and boom, cache was back! Now, the cache in the BIOS shows 8kb, but the CPU has 16kb and when you run the benchmarks, it's obvious that you have 16kb, not 8, despite what the BIOS says. Just like the BIOS doesn't show you have a DX4 installed.

You want any more details, let me know 😀

Sorry for the late reply—things have been a bit hectic lately. I totally get your hesitation with the FSB mod. I’ve been a little wary about messing with this thing myself, but I can’t resist pushing it a bit further each time. I’ll probably regret it one of these days. 😁 I really enjoy Epictronics’ videos—they remind me of the old days when there were piles of this stuff around, and I could tinker with all the “outdated” gear that neighbors and friends were tossing out. Thinking back, I realize how much “junk” I’ve thrown away over the years. I’d forgotten how much fun I got out of Frankensteining parts—stuff others saw as useless—into cool projects. It’s awesome that Major Tom was able and willing to share that mod with the community.

I still haven’t had any luck getting a POST with the CPU blaster. I’m thinking about ordering a few of those community-made PCBWay ones and trying to solder one together. I haven’t touched a soldering iron since I was 16, so I’m not sure how that’ll go—but at least I’ll have five tries, right? 🤣. Anyway, I’ll be moving on to my next project soon. I found a Tyan S2468 Thunder K7X in my garage that I’d completely forgotten about. It’s got two Athlon XP 2200+ socketed in it. I think my plan way back was to try the Athlon XP-to-Athlon MP mod, but I never got around to it. I’ll make a post about that soon once I dive in. I’d totally forgotten PCI-X was even a thing!