At 02:08 20.11.2001 -0800, Duane Maxwell wrote:
>This changeset implements an emulator for a common 6502-based
>microcomputer.

In-sane-ly great!  Very very *very* cool.

I nominate this for the hack-of-the-month award.

Upon trying HGR mode -- before I realized that the A2Morph leaves HiRes as 
an exercise for the reader -- I hit upon an undocumented instruction ($FF 
at PC $F5BA and $F5CA) when issuing a HPLOT 10,10 TO 20,20.

I *think* the 6502 did something like:

!CPU6502 methodsFor: 'undocumented' stamp: 'hh 11/20/2001 13:55'!
bbs7
         | adr v |
         "incAbsX inlined"
         adr _ self nextWordPC + x.
         memory at: adr put: (v _ (memory at: adr) + 1 bitAnd: 16rFF).
         self flagsNZ: v.
         "sbcAbsX inlined"
         self sbc: v! !

That is, a combination of INC and SBC (sometimes called "ISB").  Perhaps 
modulo *not* recognizing the D flag for the SBC, but I'll have to dig 
deeper for this.  And I have no way to tell before somebody beats me to the 
HiRes display methods.

Thank you, thank you, thank you.

Cheers,
Helge