Check the CLK line on the connector for corrosion.

PS/2 peripherals use a timing signal to synchronize with the controller. That's what CLK is for.

If the signal is weak, or spotty, devices wont initialze correctly with the port.

wierd_w wrote on 2024-11-20, 23:29:

Check the CLK line on the connector for corrosion. […]
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Check the CLK line on the connector for corrosion.

PS/2 peripherals use a timing signal to synchronize with the controller. That's what CLK is for.

If the signal is weak, or spotty, devices wont initialze correctly with the port.

I'll check on the mobo ASAP.
But shouldn't this corrosion cause issues even with the other PS/2 keyboard I was using up to a few days ago? (another vintage IBM keyboard, just a rubber dome one)

check the keyboard silly.

wierd_w wrote on 2024-11-21, 15:22:

check the keyboard silly.

Erm... The keyboard works fine on every other PC I tested it. A modernish Win 10 PC at my office, and two period correct sistems from late 90s/early 2000s I've got at home. No issues there.
The WinMe and Win2000 machines I tested it on were disconnected from power for almost two weeks now. I connected them to the socket, connected the keyboard, switched on the PSU, and booted the sistems. The keyboard worked fine from POST on both of them.

So I imagined you were talking about the PS/2 socket on the MOBO of the only PC I'm having this issue, maybe it was causing the issue only at cold boot. (also that diagram shows the female connector, thus the one on the MOBO, so it really flew over me you were talking about the keyboard).

Anyway, I'll take another look at the connector on the keyboard, since I inspected it as soon as I got the ot deliverend and looked fine.
But I also have another checklist to perform both in BIOS and in Windows boot settings, since I finally found other threads on the internet with the same issue. I'll report back with info as soon as I've checked all I have to check.

I've seen boot instability with cold boot with the model M, but the problem can easily be resolved by pushing reset, on a year 2000 motherboard. The keyboard works fine on other machines.

My only suggestion here is that the model M draws more current than later PS/2 or USB era keyboards. I think there could have been some rather weak keyboard circuits that don't initialize correctly on cold boot with such keyboards.

I have seen light dirt/corrosion be an issue, but that is easily resolve by cleaning the connector for better contact.

the3dfxdude wrote on 2024-11-21, 15:40:

I've seen boot instability with cold boot with the model M, but the problem can easily be resolved by pushing reset, on a year 2000 motherboard. The keyboard works fine on other machines.

My only suggestion here is that the model M draws more current than later PS/2 or USB era keyboards. I think there could have been some rather weak keyboard circuits that don't initialize correctly on cold boot with such keyboards.

I have seen light dirt/corrosion be an issue, but that is easily resolve by cleaning the connector for better contact.

That's also what I've been reading online, about some older keyboards needing more current to be initialised at cold boot, and not needig that at warm boot from a standby state.
A few people having issues with older PS/2 keyboard (some mentioned Model M) on MSI MOBOs. Apparently there's a solution by either tweaking BIOS settings or Windows Power settings, but I have yet to test all of them. I'll also do another pass of cleaning on the connector itself, even if it looks in pretty good conditions alredy (and doesn't have problems on other PCs).

I've got a chinese X99 board with a PS2 port and that somehow fails to work with one specific microsoft serial/ps2 mouse.
I think these new PS2 port implementations are just lacking either in protocol support or in hardware support, maybe not supplying enough power or just weirdly driving the signal lines.

weedeewee wrote on 2024-11-21, 16:00:

I've got a chinese X99 board with a PS2 port and that somehow fails to work with one specific microsoft serial/ps2 mouse.
I think these new PS2 port implementations are just lacking either in protocol support or in hardware support, maybe not supplying enough power or just weirdly driving the signal lines.

Well, as I said in the main post, this PS/2 connector is the only one on the MOBO, it's supposed to be used for either a mouse or a keyboard. So probably was put there as an afterthought.
If the issue isn't solved, I'll just get myself an active (not passive, you need for it to feed enough power to the Model M and actually translate the signal) USB adapter, wich should do the trick.

wierd_w wrote on 2024-11-20, 23:29:

Check the CLK line on the connector for corrosion.

the3dfxdude wrote on 2024-11-21, 15:40:

I have seen light dirt/corrosion be an issue, but that is easily resolve by cleaning the connector for better contact.

Checked again, no corrosion or dirt in the connector. Cleaned it just for the sake of it to no avail.

weedeewee wrote on 2024-11-21, 16:00:

I think these new PS2 port implementations are just lacking either in protocol support or in hardware support, maybe not supplying enough power or just weirdly driving the signal lines.

I tried everyithing I had listed. No setting in BIOS or windows manages to fix the issue. Even reverting to a CSM BIOS. On cold boot nothing works. The PC won't see the keyboard even for wake up via PS/2 at cold boot. But at hot boot no issues even with wake up via PS/2
I guess I have to get me an adapter... I'll report if that will fix the issue or not for future references.

Mondodimotori wrote on 2024-11-21, 18:16:

I tried everyithing I had listed. No setting in BIOS or windows manages to fix the issue. Even reverting to a CSM BIOS. On cold boot nothing works. The PC won't see the keyboard even for wake up via PS/2 at cold boot. But at hot boot no issues even with wake up via PS/2
I guess I have to get me an adapter... I'll report if that will fix the issue or not for future references.

I didn't mean to imply that you could change anything in the bios; I meant the software that runs on the little microcontroller that controls the ps2 port. It might be part of the bios, though it's more likely it's more specific and integrated into the chip that drives the ps2 port.
anyway
good luck.

I was thinking you could also try the usb adapter, and then get rasteri's HIDman - USB to PS/2 converter (Open Source) to hook the keyboard back up to the ps2 port 😀

weedeewee wrote on 2024-11-21, 18:36:

I didn't mean to imply that you could change anything in the bios; I meant the software that runs on the little microcontroller that controls the ps2 port. It might be part of the bios, though it's more likely it's more specific and integrated into the chip that drives the ps2 port.
anyway
good luck.

I know you didn't mean that. I was researching the issue all over the internet, and some people with Model M did mention that a BIOS setting "but can't remember wich one" fixed the issue. That's why I had a list of settings I wanted to test. Unfortunately none did the trick for me.

weedeewee wrote on 2024-11-21, 18:36:

I was thinking you could also try the usb adapter, and then get rasteri's HIDman - USB to PS/2 converter (Open Source) to hook the keyboard back up to the ps2 port 😀

Alredy ordered the USB adapter, but I won't trust anymore the PS/2 connector on any modern motherboard. They dropped altogheter in more recent models.

One thing to bear in mind is that a Model M draws significantly more current than most more modern keyboards (or indeed than most of its contemporaries). Most PS/2 ports should be able to handle it, old or modern, but I've also come across a few that couldnt, including my previous KVM swtich and one or two motherboards (out of multiple tens).

A USB-PS/2 adapters should be fine because USB is rated for much higher power draw than PS/2.

dionb wrote on 2024-11-21, 19:14:

One thing to bear in mind is that a Model M draws significantly more current than most more modern keyboards (or indeed than most of its contemporaries). Most PS/2 ports should be able to handle it, old or modern, but I've also come across a few that couldnt, including my previous KVM swtich and one or two motherboards (out of multiple tens).

A USB-PS/2 adapters should be fine because USB is rated for much higher power draw than PS/2.

Yeah, I read about that today, and probably my lower end AM4 MOBO with a single PS/2 port isn't rated for that much power at cold boot, but only kicks in when the PSU is on stand-by. Little weird that another lower end mobo, but from 2001, can handle this keyboard without issues. Prolly just the PS/2 standard being phased out by manufacturers. After all, I'm pretty certain my next MOBO won't have a PS/2 adapter at all, because they aren't putting them on anymore.

In the end, that USB adapter had to come in handy at some point in the near future. It really is a pleasure to write on this keyboard that I wanna keep it for my next main rig too (prolly gonna get a second one) and, when muscle memory kicks into gear, it's gonna make my neighbours mad 😅

Mondodimotori wrote on 2024-11-21, 18:50:

Alredy ordered the USB adapter, but I won't trust anymore the PS/2 connector on any modern motherboard. They dropped altogheter in more recent models.

That seems a bit much. I use original model M keyboards on current machines with PS/2 just fine. Whether they drop the plug or not due to lack of demand is not the same thing as there being a design or quality issue. I only seen the issue on one year 2000 board, and the keyboard works fine on all the other machines I used it on. The 2000 board has other issues so it aint the keyboard or that it is PS/2. But of course this is why the current draw is suspect, but the motherboard is at fault here.

the3dfxdude wrote on 2024-11-21, 21:32:

That seems a bit much. I use original model M keyboards on current machines with PS/2 just fine. Whether they drop the plug or not due to lack of demand is not the same thing as there being a design or quality issue. I only seen the issue on one year 2000 board, and the keyboard works fine on all the other machines I used it on. The 2000 board has other issues so it aint the keyboard or that it is PS/2. But of course this is why the current draw is suspect, but the motherboard is at fault here.

It's 99,9% (0,1 % margin of error) sure that's the MOBO's fault. I've tested this keyboard on four computers, with three different OS, and only on my main rig, wich also happens to be the newest one between all of them, I encounter this issue. I had to test this Model M thoroughly because it came from Ebay, with buyer protection. It wast listed as fully functional and in great external conditions. And all the tests confirm that it's indeed true: It looks basically new and works like a charm.
And I didn't encounter the issue with the other IBM PS/2 keyboard I was using up until a few days ago, but that's just a cheaper rubber dome one (still pretty decen though). So It's clearly the combination with a power hugry 1994 Model M with an MSI board that, looking around, apparently isn't new to issues with its PS/2 port. And not the only MOBO in their lineup with PS/2 issues.

My next main rig will be an AM5 board, with tons of CPU cores and a chunky GPU with tons of VRAM. And, unfortunately I may add, all the top MOBOs I can use have dropped PS/2 support entirely.

Mondodimotori wrote on 2024-11-21, 20:50:

[...]

Yeah, I read about that today, and probably my lower end AM4 MOBO with a single PS/2 port isn't rated for that much power at cold boot, but only kicks in when the PSU is on stand-by. Little weird that another lower end mobo, but from 2001, can handle this keyboard without issues. Prolly just the PS/2 standard being phased out by manufacturers. After all, I'm pretty certain my next MOBO won't have a PS/2 adapter at all, because they aren't putting them on anymore.

My one system that didn't want to work with it was a 7th gen Intel Core system, but the other was a 486 board with no USB at all. I'd say it has less with conspiracies around phasing out legacy and more with el-crappo cheap boards never haven had much headroom when it comes to specs. After all, if you wanted to ditch legacy, by that time you simply could. No-one benefits from a feature which might get used but will fail if it does. I just doubt Q&A was testing with Model Ms in 2017...

In the end, that USB adapter had to come in handy at some point in the near future. It really is a pleasure to write on this keyboard that I wanna keep it for my next main rig too (prolly gonna get a second one) and, when muscle memory kicks into gear, it's gonna make my neighbours mad 😅

They're amazing for typing (if crap for gaming due to particularly bad 2kro). I learnt to type on a 2nd gen Model M on my mother's PS/2, I now have a nice little collection, including a 1st gen XT model, which is the only keyboard I know that automatically detects XT/AT and works on either. It's now my standard testbench keyboard 😉

one thing you can check is tried to disable windows 10 fastboot feature.
since it sometime cause problem with old peripheral device.

https://www.windowscentral.com/how-disable-wi … 10-fast-startup

dionb wrote on 2024-11-21, 22:24:

They're amazing for typing (if crap for gaming due to particularly bad 2kro). I learnt to type on a 2nd gen Model M on my mother's PS/2, I now have a nice little collection, including a 1st gen XT model, which is the only keyboard I know that automatically detects XT/AT and works on either. It's now my standard testbench keyboard 😉

Luckly 2kro isn't very bad for me. I was even able to play some beatmania IIDX with it!

nhattu1986 wrote on 2024-11-22, 00:03:

one thing you can check is tried to disable windows 10 fastboot feature.
since it sometime cause problem with old peripheral device.

https://www.windowscentral.com/how-disable-wi … 10-fast-startup

It was alredy disabled.

I think (this is just speculation) that the PS/2 combo port may be causing the problem, because it may add voltage or clock to the "NC" pins (which could affect the keyboard's internal controller).
If the PS/2 port on the other machine is not a combo port, you may want to try connecting the keyboard via a splitter.

Mondodimotori wrote on 2024-11-22, 08:36:

Luckly 2kro isn't very bad for me. I was even able to play some beatmania IIDX with it!

Off topic: I didn't think I'd meet an IIDX player here...