9 Jul
1998
9 Jul
'98
10:44 p.m.
On Fri, 3 Jul 1998, Tony Duell wrote:
How wonderful it must be, to have a brain. ;)
<snip>
Nope, no 8284 that I could locate, but chip size would affect my ability
to easily spot it. I more careful inspection of the motherboard has
revealed a few smaller chips that don't have "74" on thier labels. :)
There's a 16-pin chip with "CD4050AE/RCA 227" stamped on it. There are
also six chips that sit on their sides, with 10 pins, marked
"MSP10C01-472G/DALE", and a few other minor parts.
Cool! The 6402 is located closer to the parallel port than the serial
port, though.
It lives directly between the parallel port and the 6402, so parallel I/O
it must indeed be.
It appears to be true.
<more snippage>
Cool! So the vide must indeed be on the emulator board. Which makes me
wonder what the Wang is able to do without one of those boards. The IBM
Mono Emulator board looks to have been manufactured about a year and a
half later than the motherboard.
I never did get around to hooking something up to the machine's serial
port last week. Other things came up and sucked away the time.
No 24 pin chips at all. So does the Wang have redefinable characters?
Maybe I can port some VIC-20 games to it. :)
I don't
have any kind of parts catalogue, but someone here might. Some
Yep, in my brain... P8253-5
(24-pin); Intel P8259A (28-pin); Intel D8288 (20-pin); two times
8253 is a counter/timer, probably used for a heartbeat or a real time clock
8288 = 8086/8088 bus controller IC. I'm suprised there's not an 8284
clock chip near it as well. HN482732AG-30
(EPROM, 24-pin, in 28-pin socket); D3-6402-9 (40-pin);
2732 = 4K*8 EPROM. Sounds like 4K words of BIOS
6402 _may_ be the standard 6402 UART chip. That's got 40 pins.
AM8255APC/P8255A (40-pin); SCN2661C/C1N28E/CP28028 (28-pin). The rest is
8255 = 24 line parallel I/O chip. A dogsbody sort of I/O chip. The IBM PC
uses one for the DIP switches, keyboard, sound control, etc...
There's a set of four switches right next to the 8255, and the keyboard
connector isn't too far away.
2661 is a fancy-ish serial chip. I'll have to grab
the data book to find
out more ...
It lives beside the serial port.
The board with
the funny cable connectors is labeled "LOCAL COMM D.L. BD"
and "9245 - R0M0". The only interesting IC is a 40-pin chip labeled
"WANG
2001/377-0508/IMP 03 8402BCA". The rest is TTL.
Some sort of ASIC for that strange Wang interface? are five
28-pin chips from Toshiba labeled "TC5565PC-15". There is also a
RAM, I think. Possibly video RAM. 40-pin chip
labeled "HD46505SP/HD6845SP". The rest is TTL.
6845 CRT controller (basically the timing chain for the video section).
Is there another 24 pin chip (EPROM or ROM) on this board as a character
generator? I would have expected one. Unless one of the 5565s is used for
that and loaded from disk or something. -tony
Doug Spence
ds_spenc(a)alcor.concordia.ca
http://alcor.concordia.ca/~ds_spenc/