Yo,
Mere hours after posting about searching for computer scrounging locales
in L.A., I went to "Joe Factor Sales" (corner of Burbank and Hollywood
Way), nominally a fastener house. Amongst the rows of military screws
and wall of heavy duty hoses, my companion pointed out a lone computer
board. When he pointed it out, I initially thought it was an Elf-II;
it's the same size, has LEDs and a keypad, but it was something else
entirely...
The previous owner had glued a speaker to the upper left corner, obscuring
the legend. After the proprietor had separated a fool from his money^H^H^H^H^H
sold me the board, I pried the speaker off. Underneath was...
Z80 Starter Kit
SDS SD Systems
(C) 1978 MICRO DESIGN CONCEPTS
It packs a Z80 w/PIO and CTC, 8 socketed 2101L RAMs (and room for 8 more!),
a prototyping area (with labeled address and data bits right there), and two
(unpopulated) S-100 slots (with pads for -/+16V and +8V) In addition, there's
jacks for a cassette tape drive (and buttons labelled "cass load" and
"cass
dump"), and below the ROM socket (w/masked programmed ROM "Z-BUG"), a
toggle
switch ("PGM"/"READ") and a 24-pin DIP socket marked "PRO
PROGRAMMER".
With all that, I still have questions:
o Is there any info on this? It looks much like a SYM-1 or Elf
of the day, but with a Z-80.
o What ROMs might it program? 1702? (unlikely because of a lack of
odd power supply voltages) 2708? There is a pad at one edge of
the board that snakes over to the PGM/READ button, marked +25V.
I simply do not know which particular 1978 ROMs used that particular
programming voltage.
o Why might I have heard of "Z-BUG"? Was it a famous monitor program
for the Z-80 boards of the late 70's?
o If I can't find a good use for this, does anyone want to make me
an offer for it? I promise that I won't just go out and post it
on E-overpay.
Thanks for any hints. I'd love to learn more about the history of this
thing. I just got it because it was a) affordable, b) a 1970's SBC, and
c) it has a place to add cards and my own circuits, should I decide that's
worth the effort. I could always wire on a 6164 RAM and a SCSI chip, but
then what would I do?
-ethan