War Games --> musings

[nbodley at speakeasy.net (Nicholas Bodley)]

On Tue, 21 Mar 2006 08:50:09 -0500, <markw at mohawksoft.com> wrote:

> still miss tinkering with the old Z80 systems.

 From about '82 to '86, I was fluent in Z80 assembler (Mostek FLP_80 DOS;  
their devel. system). Just came across the assembler listing (Zilog  
mnemonics, *please!*) of the program I was working on, back then; thought  
I'd lost it, long ago. Would like to have done some 6809 code; that seems  
to have been a very nice chip design, but too late.
Afaik, derivatives of the Z80 are still being sold.

Is it just coincidence that "8255" translates to "TALK" on a phone keypad?  
The 8255 was a quite-popular I/O chip from back then.

===

I also had (and might still have) the first two Pocket Computers, the  
first in a Radio Shack version of the Sharp PC-1211 (two four-bit CPUs),  
and the second a Sharp PC-1500. Fellow named Norlin Rober of Marshalltown,  
Iowa reverse-engineered the PC-1500's CPU instruction set and architecture  
(about 95% or more of it), using only a BASIC "access hole" that permitted  
direct execution of (unpublished) machine code. He sold an assembler for  
it. Sharp later gave in (imho), and published that info., but of course  
with their own mnemonics. CPU architecture was Z80-like, but significantly  
different. Little printer in the docking station was a tiny four-pen  
plotter (Alps, likely); adorable. Both: Audio cassette (1x, of course!)  
for offline storage, battery-sustained micropower RAM internally.
I have a *lot* of respect for Norlin.

Regards,

-- 
Nicholas Bodley /\ @ /\  Waltham, Mass.
"People place their hand on the Bible and swear to uphold the  
Constitution; they don't put their hand on the Constitution and swear to  
uphold the Bible."
    -- Jamin Raskin