Hi,

Do PC keyboards with "AT" connectors (the big 5-pin DIN plug)
use the same voltage levels and signalling as keyboards with
PS/2 connectors?

Will a PS/2 keyboard work if I cut off the PS/2 plug, solder
on an AT connector, and plug it into an old PC?

Otherwise, where do I get one of these? (Jameco P/N 189771):
http://www.jameco.com/webapp/wcs/sto...gDrillDownView

(Despite being listed as available, it is not.)

Hi Chris,

Chris Giese wrote:

Do PC keyboards with "AT" connectors (the big 5-pin DIN plug)
use the same voltage levels and signalling as keyboards with
PS/2 connectors?

Yes -- more or less. I.e., given that you are connecting to
an "old PC", don't expect any of the "magic buttons" common on
newer keyboards to work. In fact, don't "expect" anything
from them (including expecting them to be IGNORED).

There are a couple of different keyboard interface protocols
that the keyboard controller will/should support. Depending on
how ancient your PC is, how the BIOS handles them may vary.

Be advised many *OLD* machines didn't tolerate the keyboard
being unplugged/plugged while powered on (older keyboards
consumed more power and this often lead to the keyboard
fuse -- in the PC -- blowing; doubtful a problem with a newer
keyboard).

Will a PS/2 keyboard work if I cut off the PS/2 plug, solder
on an AT connector, and plug it into an old PC?

Depends on what you call "old". E.g., I have still some Compaq
Portable III's here (286 lunchbox).

Otherwise, where do I get one of these? (Jameco P/N 189771):

(Despite being listed as available, it is not.)

Your local computer supply place will have them. Maybe even
rat shak.

Oops. You did choose the right adapter after all. I got it wrong
because all my good keyboards are the AT type with the big plug, so I
never assumed anybody would need an adapter for an AT motherboard.

D Yuniskis wrote:

don't expect any of the "magic buttons" common on
newer keyboards to work.

Ah -- an added bonus

Depends on what you call "old". E.g., I have still some Compaq
Portable III's here (286 lunchbox).

The system in question is a Pentium 1 with 16 meg of RAM.

Your local computer supply place will have them. Maybe even
rat shak.

OK, I'll take a look.

Thanks everyone.