IBM 5160 with oddball MDA input/output card

[Tony Duell]

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