[Coco] technical assembler question

[Phill Harvey-Smith]

Arthur Flexser wrote:

> LDA #(value that depends on break key's row in keyboard matrix)
> STA $FF02
> LDA $FF03
> ANDA #(value that depends on break key's column in keyboard matrix)
> BEQ someplace (break key is being held down)
> 
> Perhaps someone here can supply the necessary row and column values, and tell me
> if I've mixed up $FF03 and $FF02 or some such.  (It's been a long time!) This is
> an excellent method for efficiently checking whether a particular key is down,
> and even works with the shift key, which POLCAT can't be used to detect the
> status of when it is the only key being held down.

Remembering of course that if you want your code to also work on the 
Dragon, you'll need to compensate for the different keyboard matrix, 
calling POLCAT, I believe does this automatically.

Cheers.

Phill.

-- 
Phill Harvey-Smith, Programmer, Hardware hacker, and general eccentric !

"You can twist perceptions, but reality won't budge" -- Rush.