Re: Silly-question

[david@wraith.cs.uow.edu.au (David E A Wilson)]

dempson@atlantis.actrix.gen.nz (David Empson) writes:
>In article <3fv1e6$hd9@wraith.cs.uow.edu.au>,
>David E A Wilson <david@wraith.cs.uow.edu.au> wrote:
>> 
>> Now if I can only work out how to read the 8th bit of the keyboard
>> ROM I could make the arrow keys send a different code from their
>> control key equivalents.

>Two minor complications there:
>1. The 8th data bit on the keyboard ROM is not connected to the data
>bus (if the circuit diagram is correct, and I think it is).

Correct.

>2. The 8th data bit in the keyboard latch is the latched key flag, not
>a bit from the keyboard ROM.

Ditto. My MPF-III (a //e clone) has an additional address to read 
the eighth bit from the keyboard. I was thinking along the lines of an
additional latch and feeding the result into the third push button input
on the internal game port. Unmodified programs would still see the same
$88 for a left arrow and control-H but modified programs could then check
PB2 (if they are numbered PB0, PB1, PB2) to see if it was the arrow key.

Any reasons for this not to work? [Does anyone still use PB2 for the shift
key mod on a //e?]
-- 
David Wilson	Dept CompSci Uni Wollongong Australia	david@cs.uow.edu.au