12 Mar
2008
12 Mar
'08
5:37 p.m.
On Wednesday 12 March 2008 20:29, Dennis Boone wrote:
UART, I think. I know I've run into that number somewhere before.
This is
clearly not the same serial interface that i have in one of my
Facits. Mine has no switches (just soldered jumpers) and half the PCB
etch is text explaining how to set them (!).
Can you give the labels on the switches on your board? And what are the
main chips on it (is it a 1602/6402 type of UART, or a
microprocessor-based circuit, or what?)
Tony,
Here's a rough list of what's on the board:
Part no 1140 68 10-00
AY-5-1013 40 pin dip (cpu?) MC14411P 24 pin dip (uart?)
Baud rate generator. Look for a crystal somewhere close to that part.
1489 line driver
27 assorted 7400 series
Various discretes, including 17 large transistors/regulators
8 wire jumpers labelled 1-8
Wire jumper labelled ERR
Place for wire jumper labelled TL
Large chrome toggle switch labelled SER/PAR/SERIAL WITH ERROR CODE on
card edge (missed the labeling on this earlier)
DB25 on card edge
8-switch dip pack labelled bit1-bit8 error code
4-switch dip pack unlabelled
5-switch dip pack labelled with baud rates 75-600
Bet you can trace some of the connections from that one to that MC14411 chip.
8-switch dip pack labelled as follows:
1. PARITY
2. 1STOP
3. NB 2
4. NB 1
5. ODD CH
6. BIT 8
7. / EVEN
GEN
8. \ ODD
Chip dates are mostly 1978.
The toggle switch, error code and baud rate stuff is all obvious. I can
figure out parity and 1stop by trial and error. For the rest I could
use some clues.
Mostly the later UARTs are programmed to set things up. Likewise a bunch of
the baud rate chips. This is earlier stuff you're dealing with here...
Anybody know who made those parts with numbers like AY-n-nnnn? I don't think
I have much data on those offhand.
--
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space, ?a critter that can
be killed but can't be tamed. ?--Robert A. Heinlein, "The Puppet Masters"
-
Information is more dangerous than cannon to a society ruled by lies. --James
M Dakin