25 Nov
2007
25 Nov
'07
11:11 p.m.
r.stricklin wrote:
On Nov 25, 2007, at 8:04 AM, Michael B. Brutman wrote:
My theory is that your machine is not 'original'. I can't tell you
which card doesn't belong .. there are a few suspects. Many of the 3270
PCs started life as floppy-only units, so the hard disk card might not
be original. Another possibility is that the memory has been upgraded
by replacing the host comm card with the memory/printer card or the
other memory card. Lastly, I'm not sure that this machine needed the
async card, but something tells me that all XT type machines that the
Async adapter in that slot. (Which I think is actually slot 8, not slot
one. There was something special about that slot.)
Anyway, an original 3270 PC (or variant) would have a 3270 emulation
board in it, and that would be connected by coax. The async adapter
would have never worked for that.
The other thing that puzzles me about the mystery card in your machine
and the eBay card is I've never seen one. IBM had a printer port on the
monochrome adapter and on the AT cards there was a parallel port/serial
port card, but I have never seen an IBM card with a parallel port and
memory. But, given the other special cards in that machine and what I
read, it seems like that is what it is.
You need somebody who has a 3270 PC guide to operations or a tech ref.
Mike
I'm digging in my secret archives. I have
just one clue so far -
somebody called it a 'printer/memory' card. Based on your description
of it and this clue, I doubt that it is the comm card for the machine.
This is the same card as mine, right here. I'm not sure I buy the
seller's description of it as a parallel printer card, though it's
certainly possible. I could accept the description if somebody were to
find some other corroborating evidence.
http://cgi.ebay.com/IBM-PC-XT-Parallel-Port-Card-ISA-Parallel-Printer-Card_…
Interestingly, it was also removed from a 5271.
Actually, the more I think about it, the more it makes sense that it's a
parallel card. Would the 5271 have been capable of using the Async
Adapter as a host interface? That's the only remaining I/O card in the
machine.
ok
bear