25 Mar
1998
25 Mar
'98
10:27 p.m.
Ithica Audio, some pretty neat systems. I used to call on them as an
apps engineer back in 1980. I wouldn't mind finding one or at least the
floppy controller as I had some influence in the design.
<> I also found a National Semiconductor Board Level Computer (BLC). It's
<> 8080A single-board computer from 1977. There's also an unpopulated RO
<> board in the small card cage. I know zilch about this one. There are
<> plenty of unconnected edge-connectors on the CPU board and an on-board
<> 8251, so I assume I can make this one fly if I simply figure out the I/
<> connections and power requirements.
IF it has two edge connectors it's multibus and it was made a few years
later as National was not in the multibus market till 79-81ish.
Allison
26 Mar
26 Mar
4:24 a.m.
On Thu, 26 Mar 1998, Allison J Parent wrote:
Ithica Audio, some pretty neat systems. I used to
call on them as an
apps engineer back in 1980. I wouldn't mind finding one or at least the
floppy controller as I had some influence in the design.
Both the floppy and floppy controller are from Micropolis in my box.
IF it has two edge connectors it's multibus and it
was made a few years
later as National was not in the multibus market till 79-81ish.
The NS BLC has a 1977 coyright on the PCB. From the component side: P1 is
the bottom left-most 86-pin (2-sided 43) connector and is plugged into the
backplane. Both boards also have an unconnected 60-pin P2 on the bottom
right.
The CPU board also has 50-pin J1, 50-pin J2, and 26-pin J3 on the top of
the card, presumably for I/O connections. It's a single-layer, two-sided
board, so I should be able to trace the pins. Some of the chips are even
labeled with their I/O address, so if I get it to come up, I might even be
able to program the thing.
-- Doug
4:24 a.m.
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5:44 p.m.
On Thu, 26 Mar 1998, Tony Duell wrote:
At a guess, the 50 pin ones are parallel I/O ports and
the 26 pin one is a
serial port (you mentioned the 8251, which is a USART chip). Try tracing
grounds and then signals (maybe to 1488's and 1489's)- you may find that a
straight IDC cable will link the 26 pin connector to a 25 pin serial port.
Don't plug it in without checking, though.
Your guesses seem correct about the function of the connectors, but I'm
not so sure about the mapping of the 26-pin connector -- they seem like
they might be reversed from what I would expect. Here are a few I buzzed:
26 - gnd
25 - transistor Q1
24 - 1488.1 (Vee)
14 - 1489.4 (2A)
13 - 1488.2 (1A), 1489.14 (Vcc)
5 - 1488.6 (2Y)
4 - N/C
3 - 1489.13 (4A)
2 - N/C
This means very little to me, other than I vaguely recall that the 1488
and 1489 are drivers (and I found a pin-out for them on the web), and I
expect ground, TX, and RX on the first three pins.
-- Doug
5:56 p.m.
New subject: NS BLC (was Re: Ithaca Audio and friends)
BTW, this other card in the small cage with the BLC that says 16K/32K
ROM/PROM appears to be a PROM programmer. It's got a program/read switch.
Of course, I have no idea how to use it, but assuming I figure it out
someday, will this thing program some ancient 1702's I've got?
-- Doug
27 Mar
27 Mar
3:02 a.m.
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26 Mar
26 Mar
4:40 a.m.
New subject: Haddock book
I had looked for the Haddock Collector's book that somebody (Uncle Roger?)
had mentioned and couldn't find it until recently:
http://members.aol.com/mtpro/bookstore.html
-- Doug
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allisonp＠world.std.com -
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yowza＠yowza.com