Big Board 1: make alive again!

Jim Brain brain at
Sun Jan 6 14:49:38 CST 2008

Enrico Lazzerini wrote:
> 1) a parallel keyboard: is it anybody could help me to transform a PS/2 or
> AT keyboard in a parallel one? Even using the only internal matrix and using
> a new keyboard encoder (I prefer less this way cause my limited free time).
> In 1983 I used KR-2376 to create the correct character codes.
Fancy you should ask that.  I just helped JP Hindin create such an 
interface for his Flashwriter II board.  It's an Atmel AVR ATMEGA8 uC 
solution, but it decodes all the PS2/AT keyboard keystrokes (including 
the funky extended ones and the really esoteric ones like Pause/Break).  
Right now, the code will convert all the main KB keys, but has open 
slots in the tables for stuff like function keys and END/HOME and the 
like.  They are easy to add, of course.  The code also detects 
CTRL/Alt/Del and creates an Interrupt (for RESET) on the IC.

Of course, I am sure there are other, more "vintage" ways to do this.  
But, it's a single IC design at present.  With a spot of effort, I could 
probably remove the need for a crystal, so it would be a 4 part design 
(1 cap, 1 pullup, 1 IC, one PS2 connector), as it is now a 7 part design 
(crystal and 2 caps)

I can provide the source and the designs if desired.


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