Uncreative Labs

Joined: 21 May 2006 Posts: 47 Location: London, England

wonder if anyone can shed light onto my latest keyboard problem Smile

My IBM XT has an original full-sized 102-key keyboard, it's identical to a Model M, except it is missing the LED panel as XT keyboards did not have support for them. Not long after I had the XT, it kept showing "xx 301" errors on bootup, but the keyboard worked properly. After a couple of days, it just shows "301" and I cannot use the keys. However! I can use the keyboard on my 486. The late XT 102-key keyboards autosensed between AT/XT standards.

Today I managed to get an identical keyboard! It was missing the SDL cable, but no problem as I have the one from the original keyboard.

It still gives the 301 error on the XT and I cannot type, exactly as the original had shown.

I tried this keyboard on my 5150, but also 301 error. I know only the later XT BIOS from 1986 supported 101/102 key keyboards, but I was wondering if it would work on an earlier machine, but just have some usless keys (like F11 and F12).

Anyway, to the point.

How can I tell if the keyboard is kaput, or if the XT motherboard somehow has a fried keyboard interface?

The confusing point is that the keyboard works perfectly on my 486!!! Otherwise I would suspect a faulty SDL cable.

Oh, it is confusing Confused

Joined: 21 May 2006 Posts: 47 Location: London, England

Just a thought, but what would happen if you plugged an AT keyboard into an XT and tried to use it? Would it damage the computer? I am wondering if my autosensing keyboard might have been stuck in AT mode by mistake.

Joined: 04 Jul 2006 Posts: 21 Location: Hollywood, Florida

Three things that may or may not help;

1. I've got a Key Tronic keyboard that came off an AT that's working with my XT - except for the ESC key

2. I think the original XT keyboard had 83 keys not 102 , and was upgraded by IBM to a 101 key keyboard around '86 or so.

3. I originally thought 5 DIN plugs automatically worked in an XT but I've found that's not the case. I have no definitive information as to what works and what doesn't. For me it's trial and error. My Key Tronic works, why , I don't know. I'm just glad it does.

Old Goat

Joined: 21 May 2006 Posts: 47 Location: London, England

I just found out that the keyboard is not working with the 486, so the problem should be in the SDL cable. I have an original 83-key keyboard on it's way for my 5150, so I can soon be able to work out where the problem lies.

The 101/102-key "enhanced" keyboard was available as an option on 1986 XT's and the BIOS was updated to support them. The standard US layout had 101 keys, the European layout had 102. The keyboard is almost identical to the Model M, except that the LED panel is blanked out. The circuit board inside even has the connection for Model M's LED panel! This enhanced keyboard was known as the "Model G". Early Model M keyboards can also autosense between XT/AT.

Joined: 03 Feb 2006 Posts: 488 Location: pennsylvanai

most x's had the 84 key board, function keys f1--f10 on the side,

at that time keyboards came in several " flavors"
the f11-f12, to my knowledge never worked on xt's or true clones, but did on tandy xt's ( which had odd scan codes)

aftermerket keyboards sometimes were compatible, some required a switch , many did not ( auto switch) ( xt-at)
try various older kb.

the switch was either obvious on the bottom or hidden in the leg of the keyboard

the black slide switch could be accidently reversed and the A-X legend could be wrong.
the switch was not screwed in , just fit on a loose bracket.

big secret: hold the kb , keys down and slap the keys all over fairly hard, all sort of junk hair paper dust staples will fall out,

slap with an open hand, pressing each key does nothing.
do it outside or in the garage or basement, not in a clean room where the wife can see you.
some kb can be dis assembled and cleaned, most cannot,

Joined: 20 Nov 2004 Posts: 589 Location: Shandong, China

I know this is an old thread, but I have been having exactly the same problems with my model M. I fixed the problem, but it wasn't as simple as a bad SDL cable in my case. I got hit with a triple whammy.

-bad keyboard cable
-bad keyboard electronics
-bad keyboard port

Reading this thread helped me isolate the problem though. I probably never would have suspected a bad cable since it seems to be so well built. Thankfully I have several other model Ms for testing. The final solution involved me swapping out the keyboard electronics from one of my working AT type model Ms.