Thanks! Seeing your wiring makes me realize what I was doing wrong with my
attempt.
On Sat, Sep 29, 2018 at 12:16 PM Jay Jaeger via cctalk <
cctalk at classiccmp.org> wrote:
The information on my Documation card reader interface
have now been
uploaded, and is available at:
https://drive.google.com/drive/folders/13KyRN4NuHIlTlBhoHiWZWmIfLwQbP5jn?us…
On 9/24/2018 5:58 PM, Jay Jaeger via cctalk wrote:
FYI, I have a design for a RS-232 interface to
the Documation M series
interface, based on a PIC 16F877. The design is in turn based on one
that does not use a PIC, that Al Kossow shared with me some time back -
and is designed to work with the same software on the PC side (at least
if I recall correctly - I did this back in 2013). [I seem to recall
that when I was testing it, I just used a terminal emulator of some
sort, so PC side software would be easy.]
The board design is in KiCAD. The "firmware" for the PIC is in C,
developed using MPLABX (freely available).
So, if anyone wants the materials, say so, and I will share a link, and
scan in my interface connector pinouts, etc., and put up a folder on my
Google Drive.
I also still have *ONE* *UNPOPULATED* board (approx. 4.25" x 2.5") that
I would be willing to part with for $10 US + S&H. As I recall, there is
one missing pull-up resistor that is wrong on the schematic (and thus
missing on the board, too), from pin 1 of the PIC to VCC, and is easy to
deal with, and that the LED labels on the silk screen are flipped around
on the board vs. the schematic [which can be dealt with easily in
software, so that the LEDs match the silk screen.] The design includes
an in-circuit programming header.
Unfortunately, the pinouts I used for the 40 pin connector on the PC
board to the card reader are NOT the same as what the Computer History
Museum has, and it makes wiring the cable a bit of a pain, because the
signal and signal return lines are not next to each other on the
connector, but should be so using a twisted pair cable.
JRJ