Keyboard PS/2 to Parallel converter - test-drb@ccmp.vtda.org

8 Jan 2008

Enrico Lazzerini wrote:
...

 Jim, 

 i need just this, I don't care to see the caps lock led turning on or off!!

 But the schematic indicated to that link, it appear to be a theoric
 schematic.

 I really have not time to testing circuit or verify how it works.

 So anybody has an idea of a pratical circuit working? 
    Yes, the schematic won't work as-is (it's only 10 bits, and PS/2 uses 11

(start, parity, stop, 8 bits) and as Holger notes, it just delivers PS/2 
Set 2 scan codes, which are horrid (voice of recent experience)

But, the design I already sent you will do exactly what you wish.  One 
Atmel Mega8 (or a Tiny24 would work, though I don't have any here to 
test the code).  Is there something else you're looking for?  I modified 
the PS2Encoder design on the web site 
(http://www.jbrain.com/vicug/gallery/PS2Encoder) to offer a truly 
generic one (all data lines come to a 2x13 header, and the PS/2 
connector is already on the board.)

I know the design works, as I tested the code before I sent someone on 
the list a version for a FlashWriter II KB interface.

...
  Holger, 

 it's exactly what i'm looking for. So may you give your help? What PIC to
 use?

 I have a PS2 Keyboard and when I press the character A I need to have the 

 binary code 41H that means 0100 0001B on eight wires plus a strobe line. 

 Only in this direction. Is it possible?

 Thanks

 Enrico
    Dave's code will work (though you'll need to write some additional 8051

code to do the parallel output, should be trivial.

My code will work, and outputs 41H when a A is sent (Actually, I think 
it sends lowercase a, but I can change the mappings in a few minutes if 
that's an issue)

Holger is speaking theoretically, without any specific design in mind, I 
believe.

Jim