View Full Version : IBM 5150 keyboard port bad?

February 23rd, 2008, 09:12 PM
Hi. I want to use an IBM 5150 to write floppies for my osborne 1(the only 5.25 drives I have besides the 5150 ones are high density drives and I think this is screwing teledisk drives). When the computer was last used about 5 years ago, it worked fine. Now,when I boot it up, I get a 301 keyboard error and then I am unable to go any further because the command interpreter is bad. I think I can fix that problem by copying command.com from the dos floppy to the hard drive,but my problem is that they keyboard port doesn't seem to work. WHen I plug a keyboard in, the only way I can get input is to jiggle the din connector(which produces garbage characters). I have tried several different keyboards, so I know it is not a keyboard issue. When I can get the pc to accept input, it is wrong i.e the '9' key shows up as '3'. I was wondering if anyone knows a fix for this. Is there a simple keyboard decoder ic I can replace, or is it more complicated. Thanks.

February 24th, 2008, 12:18 AM
Are you sure you (or someone else) didn't put it in the cassette port?

Terry Yager
February 24th, 2008, 08:40 AM
Probably as you suspected, a bad connection. Pull the board and re-solder the pins of the connector, that may fix it.


February 24th, 2008, 12:10 PM
Hi. I'm sure it's not in the cassette port. Is my only other option to resolder it then? Thanks.

February 24th, 2008, 08:08 PM
Yup, sounds like it. Cracked solder joints, especially on connectors, are fairly common on equipment, as it gets older.

Stiff joints on people. See above LOL

Terry Yager
February 25th, 2008, 07:01 AM
Yeah, the 'wiggling the wires makes it work' bit is usually a dead give-away. Anything that sticks out is especially vulnerable, all it takes is a little bump.