Re: Apple 1 microchess - correct operation?

["Keith" <chen.evans@gmail.com>]

Keith wrote:
> Does anyone have experience using the Microchess program that can be
> found at - http://www.brielcomputers.com/replica1.html?
>

One potential problem with the source that I found at
http://www.6502.org/source/games/uchess/uchess.htm is that it's using
the PHY instruction which is not in the NMOS 6502. I guess that the
Replica 1 is using the 65C02, but take advantage of the 65C02
instructions means that the code won't really run on an Apple 1. Note
that the code that is doing this is an extension to Microchess when it
was adapted to handle serial I/O.

Maybe the POM emulator should flag when illegal opcodes are used that
wouldn't have been handled by an NMOS 6502. That would help keep things
more authentic if anyone cares.

BTW - I found this instruction by trying to assemble the source code
with the Krusader assembly language development environment.

-Keith