8 Aug
2006
8 Aug
'06
3:24 p.m.
Dave McGuire wrote:
Roy J. Tellason wrote:
IX and IY are great if you are used to writing code where you deal
with lots of struct's or diddle with stack frames. For most
folks tinkering, they never figure out the value of them :-(
The z80 added stuff I've never personally
found all that useful
otherwise, and have never used the index registers (yet) or the
alternate set, all that much.
I like the index registers; I use them with some frequency. The alternate register set, though...ugh. It'd be
much more useful if the
designers had provided a way to determine which set is currently in use!
Alternate registers are useful for interrupt handlers -- *if*
you ensure that they can't be nested. You can cheat and
use AF in one IRQ and the other pairs (EXX) in another IRQ
(of course, assuming you only need AF in the one and don't
need A or F in the other! :> )