Have another look at that UART on the MITS board and see if it isn't an
AY-5-1013A. The spacing on that P2 connector is probably 0.157" (close
enough to 0.154, but ... )
I've got one of those COMUTIME FDC's, but, alas, like you, Ethan, I've got
no documentation. It should n[t be too hard to figure out, though. Among
the piles and piles of 8" floppies I have in the basement, there is at least
one labelled, (by hand) as being a Computime diskette of some sort, though
not from the mfg. I also believe I have some source code for the board
_somewhere_.
Those SSM video boards were pretty popular, though they are capable of only
16 lines of 64 characters (like the TRS-80, among others). I've still got
one, but have given/traded/sold away a couple of them.
That 24-pin DIP missing from the video board might well have been a
character generator. If you scrutinize the circuitry in that region of the
board, you might find a shift register and a data path from the RAM through
the character generator to the shift register (PISO). If you trace the data
path from the RAM, you may find it matches the pinout of either a 2513 (GI)
character generator or a 2716 (they're not the same). Whatever you learn
about that will probably be helpful.
Dick
----- Original Message -----
From: "Ethan Dicks" <erd_6502(a)yahoo.com>
To: <classiccmp(a)classiccmp.org>
Sent: Sunday, December 30, 2001 4:50 AM
Subject: Tonight's S-100 find detailed inventory
OK... first of all, let me say that an XOR box weighs a ton. Second,
here's what I have - more cards than a single computer needs. I wish
I hadn't given away _all_ of my 68K S-100 stuff to a friend years ago
(but at least it's in good hands)
In the backplane when I got it:
o COMPU/TIME UFDC-1 floppy disk controller, c. 1983
Labelled jumpers for drives A-D, each with "5/8", "S0" and
"S1"
1 34-pin connector
1 50-pin connector
WDC FD1795PL-02 FDC chip
no docs
o COEX 64K static RAM board, c. 1984
32 Hitachi M58725P 2Kx8 SRAM chips
no docs (but jumpers are labelled)
o COMPU/TIME SBC-880 CPU board (c) 1980
no CPU chip
Loose boards...
o QT Computer Systems RAM+65 SRAM board, c. 1981
32 2114 SRAMs (16K total)
missing IC49 (near the S-100 fingers, probably a 74LS240 or 74LS244)
labelled DIP switches
no docs
o Vector Graphic 8K SRAM board, c. 1980
64 2102 SRAMs
no docs
o Seals Electronics SRAM board, (c) 1976
64 2102 SRAMs (8K)
no docs
o SSM VB1C video card, c. 1980
docs
o SSM VB2 video card, c. 1979
chips still under plastic
docs
o Cromemco TU-ART Digital Interface, c. 1982
2 parallel
2 serial
NIB
docs
o Vector Graphic Bit Streamer serial card
8251 SIO chip
no docs
o MITS 88 UIO "Universal I/O Card"(?) c. 1977
M6850
AY-5-10134
26-pin Berg-styled connector
10-pin .154"(?)-spacing single-row connector (P-2)
no docs
o Unknown-brand mystery card (video?), c. 1979
8212
2 x 2708 EPROM (each marked 'FW II Gen', one with down arrow, one
up)
4 x 2114-3 SRAMs
6-pin .1"-spacing single-row connector
U42 missing (24-pin .6" DIP)
no docs
o SSM CB1A CPU board, c. 1980
INS8080A
2 x 8212
2 x 2708 (marked "0-3V" and "4.7V")
2 x 2114
docs
o SSM 8080 Monitor V1 docs
command summary
listings
So, all in all, a good night's work. I'd love to learn more about
what I have, especially the stuff with no docs. Some of the docs
I do have, have schematics, but some of it is assembly and rudimentary
test/programming instructions.
I would appreciate any and all tips to online versions of docs for
this stuff. I would also appreciate any tips for getting an OS for
the box with its COMPU/TIME cards. I suppose one way would be to
receive a 5.25" image, reconstitute it and boot the system off of
mini-floppy, then format a disk or two on the 8" floppies and go
from there.
-ethan
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