!KBDATA is ignored and yes, the signal levels are basic TTL. Where is your schematic located?

Don't forget that the 9100 needs to register the keyboards response to !KBRESET when you are coding this up. Data rate is 1200 Baud.

John :-#)#

At 10:59 AM 02/06/2003 -0700, David Shoemaker wrote:

Kev pointed me at the right page on the schematics (page 163 in the 9100_svc_part2.pdf). Looking at the schems I think this project just got easier.

I was expecting to have to use a MAX232 (or similar) TTL (0 - 5v) to RS232 driver chip (+/- 3v). But looking at the 9100 schematic the keyboard signal is just fed to a 74HCT14 / 74LS04 pair which raise the levels back to TTL. So I think I can just drive this at TTL levels directly from the microcontroller. Currently looking at one of the small Atmel parts.

So this becomes a single chip solution. I like it.

Anyone want to take a look at the schematic and vet my answer? Also it looks like though !KBDATA is at pin 1 it just gets fed to ground so I only need to feed KBDATA.

Now all I need to do is figure out what BAUD rate the 9100 is expecting its data at.

David