World: r3wp

Flags are calculated on the last accumulator value if i don't do 
mistakes

ok. One optimization, I consider, is to cross-compile 6502 opcodes 
to rebcode, instead of emulating the 6502. That won't work with self-modifying 
code and branches will be a problem. So it's hard, but I think, it 
might work.

in theory

i give you an example with the TAX opcode

; updating flags in real time

label TAX
seti X A
eq X 0
either [or P 2] [and P 253]
seti i X
and i 128
eq i 128
either [or P 128] [and P 127]
bra continue

;  delay the calcul of flags

label TAX
seti X A

or maskA (2 + 128)     ; remember that we have to recalculate zero 
and negative flags using A, but don't do it now
bra continue

Thanks!

you got the idea ? ;-)

Yup! :)

did you think that using PC as an offset (integer) instead of as 
a serie could be faster ?

I should do a test before saying that

I didn't consider much in deep actually. It can be improved, I'm 
sure. :)

anyone happes to still have a rebol/core binary with rebcode functionality 
archived somewhere?

it's not in the download section of rebol.com anymore ?

ah, got it: http://www.rebol.net/builds/042/rebview1350042.tar.gz

resp. http://www.rebol.net/builds/031/rebview1350031.exefor windows