Date   : Sat, 21 Oct 1989 22:30:12 GMT
From   : mcsun!unido!cosmo2!tilmann%cosmo.UUCP@uunet.uu.net (Tilmann Reh)
Subject: Z280

Hello to all the "old cp/m users"!

As far as I can see in the last entries here, there is a big discussion
about Z80/180/280. I'm very glad to see that because I am just designing
a very nice Computer Board with the Z280.
Here is just a technical shortform:
Z280 in Z-bus-mode (16 bit) driven with maximum clock speed (at this time,
10 MHz), ECB-bus-support for 8-bit-I/O with a bus clock of half the cpu 
clock, on-board RAM (1 meg) and EPROM (128 k), real-time-clock with alarm
and 50 byte nvram, 2 rs-232 with handshake, FDC for up to four drives.
The circuit design seems to be ready (and steady) now, so I'll start with
the layout (single-board europe card) in the next days or weeks.
I'll implement CP/M-3 with some features concerning floppy-i/o etc. (auto-
matic disk exchange recognition, automatic format adjust) just as it works
in my 64180 system (self-designed, too) since nearly 3 years.
I found some interested people here (germany) in our cp/m user's group, 
and I'd like to know if there are more.
Please contact me if you are interested or if you have special ideas for
the circuit design or layout.

Just another theme:
I am programming an ARC utility for CP/M in Turbo-Pascal. I got the sources
from Reimer Mellin and optimized them to take 4k less code and to work about
3 times faster. I am now planning to add the compression methods "squeezing"
and "squashing", but I don't have any kind of algorithm or description of
these methods. Please, keep your eyes open and contact me if there are any
papers about these compression methods.
The result of my work will be public domain. Maybe I'll program an assembler
version of ARC (Z280-Code?) as soon as I get the time.

This is especially for YOU, DOUG and JAY:
I heard something about you were engaged in the lovely Z280, too. I would
like to post my design to one of yours, and to get all information you've
yet worked out. So we could each take advantage of the other's ideas.
What do you think about it? Please let me know (or post your knowledge):
       Tilmann Reh
       In der Grossenbach 46
       D-5900 Siegen
       WEST GERMANY

Tilmann Reh  (tilmann@cosmo.uucp)