MaxZ80, the Sequel

I posted something in the group a while back on a tutorial on Z-System
I wrote and I'd like to tell you what's changed.

Before I do that, I'd just briefly like to say I've been watching the
here but not reading the details (yet). The stuff on the P112, the
and the references to the SIMH Altair 8800 (Z80) simulator are totally
fascinating to me. CP/M is alive and well.

Two basic things have changed in my tutorial: the software that is
in the downloadable self-extracting archive that is mentioned in the
chapter and the text in the first chapter.

These changes were motivated by something I spotted here, namely the
Altair 8800 (Z80) simulator by Peter Schorn. I used to own a real
Altair 8800
so when I learned somebody had written a simulator for it, I had to
take a
look. This all led to my finally jumping into Linux (the simulator has
both a
Windows version and a Linux version). I chose Xubuntu and managed to
an ISO image and burn a CD and then boot off of it. After playing with
it I
chose to put it on my Windows 98 Gateway computer's hard disk,
splitting it
into about 8 MB for Windows, 6 MB for Xubuntu. Then I downloaded the
simulator and installed it (I know very little Linux but apparently
enough to succeed at this task). Then the fun started.

Two things needed to be solved. How do I get a clock module in it so I
datestamp my files under Z-System? And why don't some of my programs
that do
stuff like graphics characters and delete from cursor to end of line
etc. work? Both of these problems have now been solved. And it took
Schorn and Howard Goldstein to solve them. Peter sent me source code
for the
clock driver that he got from his ZSDOS.ZIP package, Howard fixed a
bug in it
and we had a working clock. The other problem was simply solved by
what is called a better .Z3T file than the one Peter was distributing.
are "TCAP," or "Terminal Capabilities" files which contain escape
for specific terminals. The sequences clear screen, home cursor,
delete from
cursor to end of line etc. Second problem solved.

Finally, the key thing that I had totally forgotten about was the
of Joe Wright, Bridger Mitchell and Jay Sage's NZCOM. This is now
under GNU
license but I purchased it way back and built my Z-Systems with it. My
tutorial had a Z-System image that I could not for the life of me
how I built it. It now uses a different DOS (ZSDOS), it has a slightly
so-called NZCOM User Area to accommodate the clock stuff, a
better .Z3T and
all the parts can be loaded with NZCOM.

Maybe the most important thing here is how crucial it is for people to
together to solve problems. To give feedback when you're stuck.

Throughout all this one other interesting thing happened. An old
friend who
used to spend time on a bulletin board I used to run asked me if I had
machine readable files that captured the messages that were passed
back and
forth in the 1990s. I looked and could not find any. Then, quite by
I found hardcopy of a bunch of messages. So I scanned them and posted
for him. On top of all this, right next to these PBBS message board
I spotted hardcopy of COPY.MAC, the source code to the program Ken
developed in his book "CP/M Assembly Language Programming." I've
always been
ticked I could not find executable or source to this program. I
learned CP/M
from this book, a learning by doing book. I OCRed the 8 pages and then
the usual edits you need to to fix the things that didn't come across
right and got it to assemble. If anybody is nostalgic enough to want
to see
what was going on on "Z-Node #12" in December 1990 and / or needs a
brush up
course on CP/M fundamentals, you may check out

There's a link in the above to the COPY program I mention above. I
also snuck
COPYKB.COM and COPYKB.ASM into A1:COMS in my tutorial.

Lee Bradley