26 Jul
2019
26 Jul
'19
4:23 a.m.
Hi all,
Someone on one of the Facebook vintage groups found an IBM 5160 with an MDA
display for sale in Australia, except that it's a bit odd in that the
machine had what appears to be an MDA card, the output of which is then
connected via a short external cable to the input on another card, and then
an output that card is what's actually hooked up to the monitor.
The only internal photo of the machine is very poor, unfortunately. I'm
reasonably confident that the "first" card in the "mystery" chain is
MDA,
it's full-length and alongside the DE-shell video output has the usual
DB-25 for parallel. The "mystery" card is also full-length, and there's
another full-length card immediately adjacent to it with no external
connectors - that one could easily be RAM, or the hard disk controller etc.
but I suppose it's possible that the mystery item is actually a two-card
set.
Anyway, any guesses as to what it might be? The implication is that the
mystery card adds functionality to the MDA card (reminiscent of 3DFX boards
years later), but of course is operating within the confines of what the
MDA display's capable of.
cheers
Jules
26 Jul
26 Jul
7:50 a.m.
On Fri, Jul 26, 2019 at 12:23 PM Jules Richardson via cctalk
<cctalk at classiccmp.org> wrote:
Hi all,
Someone on one of the Facebook vintage groups found an IBM 5160 with an MDA
display for sale in Australia, except that it's a bit odd in that the
machine had what appears to be an MDA card, the output of which is then
connected via a short external cable to the input on another card, and then
an output that card is what's actually hooked up to the monitor.
Are you sure it's MDA rather than CGA. The reason I ask is that I have a
full-length 8-bit ISA card in my collection that connects between the CGA
card and its monitor (it also provides a composite video output if you want
that) _and_ inside the machine it connects between the floppy controller and
the drives.
There's a 6502 processor on said card and it claims to provide an emulation
of the Apple ][
If yours is MDA then I wonder if it's some graphics add-on (remember
the original
MDA was text only). But most of those, like the Hercules, provided the text mode
as well and were stand-alone cards. It wasn't much extra logic to do that.
-tony
10:47 a.m.
On 7/26/19 9:50 AM, Tony Duell wrote:
Are you sure it's MDA rather than CGA. The reason
I ask is that I have a
full-length 8-bit ISA card in my collection that connects between the CGA
card and its monitor (it also provides a composite video output if you want
that) _and_ inside the machine it connects between the floppy controller and
the drives.
Hi Tony,
The person who was asking about it said that it's a 5151 display, although
I've not seen any photos showing the front of the machine/monitor, so I
can't be 100% certain. Having said that, the lower part of the monitor's
back is visible in one photo, and it has captive power + video cables off
to the left and no controls, which seems consistent with a 5151; I believe
that the 5153 and 5154 had a power socket and brightness/contrast controls
on them.
There's a 6502 processor on said card and it claims to provide an emulation
of the Apple ][
That's an interesting beast. I did wonder if this was something along those
lines, too, i.e. a non-x86 processor card for the purposes of emulating
something else - but the only one I'm aware of is the XT/370, and I don't
believe that did any kind of video pass-through (that and I think it was a
three-board set, where this is two at most).
If yours is MDA then I wonder if it's some
graphics add-on (remember
the original
MDA was text only). But most of those, like the Hercules, provided the text mode
as well and were stand-alone cards. It wasn't much extra logic to do that.
Indeed. Whatever it is still appears to run within the limits of the MDA
display, so it's not color, and resolution-wise it must be more or less in
line with Hercules. As you say, there wasn't a massive increase in logic
when comparing Hercules to MDA, so it seems odd for a card to exist which
still required an MDA adapter to be present; I feel there's got to be some
additional functionality being offered, too.
cheers,
Jules
27 Jul
27 Jul
4:28 p.m.
On 7/26/2019 12:47 PM, Jules Richardson via cctalk wrote:
That's an interesting beast. I did wonder if this was something along
those lines, too, i.e. a non-x86 processor card for the purposes of
emulating something else - but the only one I'm aware of is the XT/370,
and I don't believe that did any kind of video pass-through (that and I
think it was a three-board set, where this is two at most).
The XT/370 proper was a two board set: a processor card (P-Card) and a
memory card (M-Card). The XT/370 also came with a 3270 coax terminal
emulation card, which might be the card you are thinking of. (And no,
the XT/370 did not have anything special, video-wise).
The 3270/PC had a special setup where the keyboard connected to a
special connector, which connected to a special keyboard card, and also
to the normal PC keyboard connector -- but nothing like what you are
describing (it was only a DB9 or 15).
JRJ
26 Jul
26 Jul
9:25 a.m.
On Fri, 26 Jul 2019 at 13:23, Jules Richardson via cctalk
<cctalk at classiccmp.org> wrote:
Someone on one of the Facebook vintage groups
Oh? Which one?
--
Liam Proven - Profile: https://about.me/liamproven
Email: lproven at cix.co.uk - Google Mail/Hangouts/Plus: lproven at gmail.com
Twitter/Facebook/Flickr: lproven - Skype/LinkedIn: liamproven
UK: +44 7939-087884 - ?R (+ WhatsApp/Telegram/Signal): +420 702 829 053
10:50 a.m.
On 7/26/19 11:25 AM, Liam Proven via cctalk wrote:
On Fri, 26 Jul 2019 at 13:23, Jules Richardson via
cctalk
<cctalk at classiccmp.org> wrote:
It's in Vintage Computer Club, posted on the 24th. Doubtless Facebook's
buried it for you because it seems to enjoy hiding info from people
whenever possible these days, but a search within the group for "5160" will
presumably find it.
cheers,
Jules
Someone on one of the Facebook vintage groups
Oh? Which one? 
12:53 p.m.
On Fri, 26 Jul 2019, Jules Richardson via cctalk wrote:
Someone on one of the Facebook vintage groups found an
IBM 5160 with an MDA
display for sale in Australia, except that it's a bit odd in that the machine
had what appears to be an MDA card, the output of which is then connected via
a short external cable to the input on another card, and then an output that
card is what's actually hooked up to the monitor.
The only internal photo of the machine is very poor, unfortunately. I'm
reasonably confident that the "first" card in the "mystery" chain is
MDA,
it's full-length and alongside the DE-shell video output has the usual DB-25
for parallel. The "mystery" card is also full-length, and there's another
full-length card immediately adjacent to it with no external connectors -
that one could easily be RAM, or the hard disk controller etc. but I suppose
it's possible that the mystery item is actually a two-card set.
Anyway, any guesses as to what it might be? The implication is that the
mystery card adds functionality to the MDA card (reminiscent of 3DFX boards
years later), but of course is operating within the confines of what the MDA
display's capable of.
Genlock?
MOST video add-ons were combined onto a board with their own video card,
rather than connecting to IBM's
Co-processor?
Diamond Computer Trackstar was an Apple2 on an ISA card.
It was even sold [briefly] by Radio Shack.
Quadram Quadlink was an Apple2 on an ISA card. The college bought
20 of them. 14 were DOA. 8 of the replacements ("THESE ones are
thoroughly tested") were also DOA. One had a connector (right angle dual
row?) mounted backwards, and could not be connected for testing.
But, MDA (or MDP as described) seems less likely. "Who would want to do
Visicalc or word processing without COLOR??" There did exist a few
after-market CGA cards that had DE9 and DB25 (printer).
Was it in working order? Or had somebody merely cabled the MDA video to a
DE9 serial port? And 5151 will physically connect to CGA (and not work)
We had a couple of "instructors" at the college who didn't see anything
wrong with connecting any cables that fit, including swapping bus mouse
and video, or wanting gender changers to try to connect a parallel
printer to a 25 pin serial port ormodem to printer port. It is
frustrating to try to deal with some people.
1:04 p.m.
On 2019-07-26 4:53 p.m., Fred Cisin via cctalk wrote:
On Fri, 26 Jul 2019, Jules Richardson via cctalk
wrote:
I know of a "trained" service technician who inserted an PCI card into a
ISA card slot and then call for assistance because it did not work.???
Fix.. swap technician...
Paul.
Someone on one of the Facebook vintage groups
found an IBM 5160 with
an MDA display for sale in Australia, except that it's a bit odd in
that the machine had what appears to be an MDA card, the output of
which is then connected via a short external cable to the input on
another card, and then an output that card is what's actually hooked
up to the monitor.
The only internal photo of the machine is very poor, unfortunately.
I'm reasonably confident that the "first" card in the "mystery"
chain
is MDA, it's full-length and alongside the DE-shell video output has
the usual DB-25 for parallel. The "mystery" card is also full-length,
and there's another full-length card immediately adjacent to it with
no external connectors - that one could easily be RAM, or the hard
disk controller etc.? but I suppose it's possible that the mystery
item is actually a two-card set.
Anyway, any guesses as to what it might be? The implication is that
the mystery card adds functionality to the MDA card (reminiscent of
3DFX boards years later), but of course is operating within the
confines of what the MDA display's capable of.
Genlock?
MOST video add-ons were combined onto a board with their own video
card, rather than connecting to IBM's
Co-processor?
????Diamond Computer Trackstar was an Apple2 on an ISA card. It was
even sold [briefly] by Radio Shack.
????Quadram Quadlink was an Apple2 on an ISA card.? The college bought
20 of them.? 14 were DOA.? 8 of the replacements ("THESE ones are
thoroughly tested") were also DOA.? One had a connector (right angle
dual row?) mounted backwards, and could not be connected for testing.
But, MDA (or MDP as described) seems less likely.? "Who would want to
do Visicalc or word processing without COLOR??"? There did exist a few
after-market CGA cards that had DE9 and DB25 (printer).
Was it in working order?? Or had somebody merely cabled the MDA video
to a DE9 serial port?? And 5151 will physically connect to CGA (and
not work)
We had a couple of "instructors" at the college who didn't see
anything wrong with connecting any cables that fit, including swapping
bus mouse and video, or wanting gender changers to try to connect a
parallel printer to a 25 pin serial port ormodem to printer port.?? It
is frustrating to try to deal with some people. 
1:21 p.m.
I have been out of the PC tech game for almost 20 years and even I know the
difference between ISA, PCI, MCA and AGP. I've never actually seen an EISA
in the flesh though.
Ray
On Fri, Jul 26, 2019, 4:04 PM Paul Berger via cctalk <cctalk at classiccmp.org>
wrote:
On 2019-07-26 4:53 p.m., Fred Cisin via cctalk wrote:
On Fri, 26 Jul 2019, Jules Richardson via cctalk
wrote:
I know of a "trained" service technician who inserted an PCI card into a
ISA card slot and then call for assistance because it did not work.
Fix.. swap technician...
Paul.
Someone on one of the Facebook vintage groups
found an IBM 5160 with
an MDA display for sale in Australia, except that it's a bit odd in
that the machine had what appears to be an MDA card, the output of
which is then connected via a short external cable to the input on
another card, and then an output that card is what's actually hooked
up to the monitor.
The only internal photo of the machine is very poor, unfortunately.
I'm reasonably confident that the "first" card in the "mystery"
chain
is MDA, it's full-length and alongside the DE-shell video output has
the usual DB-25 for parallel. The "mystery" card is also full-length,
and there's another full-length card immediately adjacent to it with
no external connectors - that one could easily be RAM, or the hard
disk controller etc. but I suppose it's possible that the mystery
item is actually a two-card set.
Anyway, any guesses as to what it might be? The implication is that
the mystery card adds functionality to the MDA card (reminiscent of
3DFX boards years later), but of course is operating within the
confines of what the MDA display's capable of.
Genlock?
MOST video add-ons were combined onto a board with their own video
card, rather than connecting to IBM's
Co-processor?
Diamond Computer Trackstar was an Apple2 on an ISA card. It was
even sold [briefly] by Radio Shack.
Quadram Quadlink was an Apple2 on an ISA card. The college bought
20 of them. 14 were DOA. 8 of the replacements ("THESE ones are
thoroughly tested") were also DOA. One had a connector (right angle
dual row?) mounted backwards, and could not be connected for testing.
But, MDA (or MDP as described) seems less likely. "Who would want to
do Visicalc or word processing without COLOR??" There did exist a few
after-market CGA cards that had DE9 and DB25 (printer).
Was it in working order? Or had somebody merely cabled the MDA video
to a DE9 serial port? And 5151 will physically connect to CGA (and
not work)
We had a couple of "instructors" at the college who didn't see
anything wrong with connecting any cables that fit, including swapping
bus mouse and video, or wanting gender changers to try to connect a
parallel printer to a 25 pin serial port ormodem to printer port. It
is frustrating to try to deal with some people.
3:15 p.m.
On 7/26/19 2:53 PM, Fred Cisin wrote:
Genlock?
MOST video add-ons were combined onto a board with their own video card,
rather than connecting to IBM's
It seems odd within a 5151/MDA context though - plus the system seems
entirely self-contained, i.e. not designed to interact with any other video
equipment.
Co-processor?
????Diamond Computer Trackstar was an Apple2 on an ISA card. It was even
sold [briefly] by Radio Shack.
????Quadram Quadlink was an Apple2 on an ISA card.? The college bought 20
of them.? 14 were DOA.? 8 of the replacements ("THESE ones are thoroughly
tested") were also DOA.? One had a connector (right angle dual row?)
mounted backwards, and could not be connected for testing.
Something like that is certainly sounding plausible to me - not necessarily
Apple II, but *something* that provides non-x86 processor ability, and
presumably which involves video output above and beyond MDA (otherwise why
wouldn't it drive the MDA card directly), and yet still monochrome and
compatible with a 5151.
But, MDA (or MDP as described) seems less likely.?
"Who would want to do
Visicalc or word processing without COLOR??"? There did exist a few
after-market CGA cards that had DE9 and DB25 (printer).
I did manage to locate the original seller's listing, which didn't really
provide any new information - but there were a couple of pictures of the
monitor confirming that it is a 5151.
Was it in working order?? Or had somebody merely
cabled the MDA video to a
DE9 serial port?
The thought had crossed my mind, too. Seller's claim was that they had it
booted to a DOS prompt, then smoke came out of the PSU; if they're honest
then it's likely age-related demise of RF suppression caps or maybe a
tantalum somewhere.
I did get the impression that they don't really know what they have, i.e.
to them it's just an old XT (and therefore worth a small fortune).
The cable connecting the MDA's output to the mystery card does rather look
like it was made for the purpose - it's conveniently long enough to bridge
between one or two slots, and the cable appears to exit the connectors at a
45 degree angle to account for the MDA's output being toward the top of the
card while the input to the mystery card is toward the bottom.
We had a couple of "instructors" at the
college who didn't see anything
wrong with connecting any cables that fit, including swapping bus mouse and
video, or wanting gender changers to try to connect a parallel printer to a
25 pin serial port ormodem to printer port.?? It is frustrating to try to
deal with some people.
I suppose that's the only good thing about the modern "everything is USB"
world... :/
cheers
Jules
1975
days inactive
1976
days old
9 comments
7 participants
participants (7)
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