> What does an IBM AT ! keyboard transmit when you press a key ?
> I monitored this on a scope and it looks like a synchronous 11 bit signal.
> Anyone who has a list of the codes emitted for all keys in a 101 or 102 key
> keyboard ? (i'm not talking about the scancodes here. Because they are
> generated
> inside the PC by the keyboard controller on the motherboard.)
>
> I figuered out that each key has 2 codes. One of the bits seems to indicate
> Key
> pressed or Key released. There also seems to be something like parity
> control.
>
> The target application is a small process controller that can either
> interface
> to a VT52 terminal. Or interface to an IBM-PC (AT !) keyboard and LCD
> display.
>

In the Philips Semiconductors book "Application Notes for 80C51-Based
8-Bit Microcontrollers" there is an application note AN434 "Connecting
a PC keyboard to the I2C-bus".

It  has a description of what comes out of it, how to connect to it
as well as a software listing.

Regards

Peter
--
_______________________________________________________________________
Peter Homann                                email: peterh@adacel.com.au
Adacel Pty Ltd                              Work : (03) 596-2991
250 Bay St, Brighton 3186, VIC, AUSTRALIA   Fax  : (03) 596-2960