pwh@gitpyr.UUCP (Phil Hutto) (01/28/85)
I'm in the process of designing and building and emulator for IBM PC Assembler.
First thoughts make me believe that this shouldn't be too difficult but it's
a little bit outside of my usual line of programming. If anyone has experience
writing similar code I'd be grateful for any word of advice or (especially)
warning. It seems the only really tricky things should be handling interrupts.
Thoughts?
phil hutto
--
Phil Hutto
Georgia Insitute of Technology, Atlanta Georgia, 30332
...!{akgua,allegra,amd,hplabs,ihnp4,seismo,ut-ngp}!gatech!gitpyr!pwhroy@phri.UUCP (Roy Smith) (01/29/85)
> I'm in the process of designing and building and emulator for IBM PC > Assembler. It seems the only really tricky things should be handling > interrupts. > Phil Hutto {akgua,allegra,amd,hplabs,ihnp4,seismo,ut-ngp}!gatech!gitpyr!pwh I once wrote (as a class project) an emulator for a mythical (fairly simple) machine architecture. The hardest part was setting the overflow flag. C doesn't support any way (that I know of) to detect carry/overflow. I ended up writing litle host-assembler (this was on a pdp-11) routines to do the arithmetic operations and return the result and also set the condition codes. Fortunately, the mythical machine did 2s-complement arithmetic. -- allegra!vax135!timeinc\ cmcl2!rocky2!cubsvax>!phri!roy (Roy Smith) ihnp4!timeinc/