i was always one for a challenge:
perhaps this is a newbie asm question but I always thought al/ah were 8 bit registers- is this my old asm experience talking? could it be the "new" intel "standards". hmmmmm....well, I've seen stranger Mac asm, so, for the challenge, I'll assume 24 bit registers, I guess....
I just followed my thoughts through- here they are:
- and al,00fh: sets first 16 bits of al to 0, last 8 bits are left as they were
- add al,090h: adds one gross (144=9*16) to al, which makes al now 09x where x is from the original set
- daa: decimal adjust after addition: changes al to a packed decimal number stored in hex- results in 90+x as decimal packed into hex
- adc al,040h: adds dest to src and carry flag, too: (90h+xh)+40h
- daa: like (90+40)+x=130+x packed BCD
hmmm, can this be right? probably not, oh well. I find it amusing that CISC processing leads to infinite obfuscation- much more than perl could ever achieve. (www.assemblymonks.org?)
/me decides that perl is better than assembly.
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