CP/M survey

[Allison]

>
>Subject: Re: CP/M survey
>   From: "Chuck Guzis" <cclist at sydex.com>
>   Date: Wed, 18 Apr 2007 23:35:31 -0700
>     To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org>
>
>On 18 Apr 2007 at 17:17, Allison wrote:
>
>>> I'd do the bios development on one of the existing long list of 
>systems.
>> All of my listed systems work especially the CP/M hardware.
>
>Not me--I do it under emulation on a nice speedy windoze system.   
>It's amazing how fast MAC will munch code running on a software 
>emulator.

:)  I do have Myz80 and Dave Dunfeilds NS Horizon emulator as tools
for when I'm purely messing with code.  But when I have a hefty
10mhz z80 S100 crate next to the PC with solid tools and a good 
programmer in it why mess with a PC.

>> Qualifies as an 8080!  With a bunch of Pc hardware to impair it.  ;)
>
>Maybe, but ti couldn't run JRT Pascal.  AFAIK, the only commercial 
>product that ever used the bizarre coding sequence:
>
>    LXI	SP, PROC-1
>    CALL	PROC

JRT Pascal was Z80 code if memory serves.  But LXI SP, value is
valid as the arithmetic is done at compile time not execution. 
Loading a stack address prior to a call is ok if you need to 
recover the stack content (for recursion or some such) but
I'd expect prior code to save/restore the stack or the routine 
making the call will return to nowhere.   I've seen a lot of 
code that mucks with the stack in the past and it's ok if you 
remember your return addresses are on that pile!

I've not encounterd this problem with V20. That sequence is 
not so strange to me.  though I've not used JRT Pascal (or 
many other high level) tools on a V20 because I haven't found
that a V20 XT PC to be all that great compared to a 4mhz z80. 
I have been meaning to try the Tandy 1000HX which has a V20 
and see if thats better.  In the end running an 8080 (V20) 
when I have Z80 or even fast(6mhz HmosII) 8085s is sort of 
less than interesting.


Allison