First post, by Rincewind42
Hi, I just put together a new Socket 7 Pentium MMX machine that has an AT-style keyboard connector. When I connect an old AT keyboard to it, it naturally works fine. I bought a few PS/2 keyboards from eBay that I'm trying to use via a PS/2 -> DIN adapter because that AT keyboard is a bit worn out.
These are my findings:
- AT keyboard -- works perfectly fine
- Kensington "Comfort Type" ergonomic PS/2 keyboard -- works perfectly fine with a simple PS/2 -> DIN adapter
- Diamond Digital PS/2 keyboard -- works, kinda... but certain key combinations result in extra characters being typed in the DOS prompt and sporadic PC speaker beeps, then continuosly holding down keys (like in games) results in lots of beeps and extra characters that I did not even press
One would think the keyboard is simply faulty, but nope. I happened to buy TWO used Diamong Digital keyboards (yeah...), and both have the exact same issues. Moreover, when I connect these keyboards to my modern PC that happens to have PS/2 connectors, they work flawlessly.
So, it's clearly not my adapter nor my motherboard as the old AT and the Kensington PS/2 with the adapter work 100% fine. As the Diamond Digital works fine with a modern PC but not with the old Pentium, I can only think that the PS/2 standard has slightly changed over time, perhaps? Or the Diamond Digital does not 100% follow the standard, and old motherboards were more sensitive to such things?
In any case, out of the 3 keyboards I bought 2 are now useless... And this worries me because if I keep buying PS/2 keyboards online without the option to test them first, apparently there's a non-zero chance that I might get one incompatible with my old Pentium board.
Have you guys encountered such issues before? More importantly, a) is there a fix for such PS/2 keyboards to make them work with older machines, b) is there a list of known good PS/2 keyboards or something that are guaranteed to work with old machines? I'd hate to shell out more $$$ on another keyboard just to find that it works fine with modern machine but not my old Pentium... Thanks!
DOS: Soyo SY-5TF, MMX 200, 128MB, S3 Virge DX, ESS 1868F, AWE32, QWave, S2, McFly, SC-55, MU80, MP32L
Win98: Gigabyte K8VM800M, Athlon64 3200+, 512MB, Matrox G400, SB Live
WinXP: Gigabyte P31-DS3L, C2D 2.33 GHz, 2GB, GT 430, Audigy 4