Re: Writing emulator...

[steve@dosius.zzn.com (Dosius)]

Mike Guidero <mike@bogus.net> wrote in message news:<uoc1k0bnt7qc6e@corp.supernews.com>...
> Dosius wrote:
> > Not sure, because the manual did say this - but if I omit them, I get
> > different results - yes, I get CP/M, but the output is garbled.
> 
> The manual is correct, but it's handled in software.  If you disassemble the 
> code that 60k CP/M 2.23 puts in $3C0-$3DB and $E3F-$E4A, you get this:
OK, I'll disable it in 0.74 and later

> > but if I omit them, I get
> > different results - yes, I get CP/M, but the output is garbled.
> 
> How is it garbled?  I read on your site that there is a problem with a 
> "phantom" 80-column card.  
That is fixed: try the ProDOS User's Disk and see what's in slot 3. 
In earlier versions this said "80-column card", but now it says
"empty".

> That could well be your garbled display problem, 
> since CP/M attempts to enable any card in slot 3 for console I/O.  If it 
> does not find a display card, it uses Apple monitor routines to do keyboard 
> and display.  When CP/M is doing I/O, it is always using 6502 code for it.
It's hard to explain.  

Did you say you used Linux?  Dapple could possibly work in dosemu...

> 
> Another thing to note: Microsoft CP/M versions prior to 2.23 do not follow 
> the Pascal slot protocol.
> 
> Mike

???

(can you tell I know next to nothing about the hardware?)