Some time ago I was looking to adapt an NCR4950 keyboard that I came across to USB from its proprietary ADDS format. Some users informed me that this was possible, and even did so themselves! They provided some steps on how to do so that they had written up initially, but I unfortunately did not have as much success. Here is a link to the old thread :viewtopic.php?t=19421.
Of course, some time has passed and I happen to have quite a bit more free time now (though not by much...). I was looking to adapt this keyboard once more as it has only gained dust in its box since I received it those years ago.
I got around to ordering an ATMEGA32u4 as my microcontroller to do the heavy lifting with this, and I wired it up as follows (provided the very useful guide provided by user theinversekey, thanks again!viewtopic.php?f=7&t=19692). I used the original teensy to actually program my IBM Pingmaster (which is working well at annoying my coworkers
)Current wiring:
NCR - ATMEGA32U4
Pin 6 (reset) - RST
Pin 5 (data) - PIN3
Pin 4 (gnd) - NA
Pin 3 (clk) - Pin 2
Pin 2 (sg gnd) - GND
Pin 1 (vcc) - VCC 5V
Here are some photos as well to illustrate the PCB and the current wiring a bit better:
I am currently attempting to use a USB to Soarers converter hex code to adapt the keyboard, however I have had no success with receiving any key presses after the flash to the microcontroller. QMK Toolbox correctly recognizes the converter, however it appears to be in "XT" mode, which I assume must be changed over to AT to work properly with this keyboard. Unfortunately, I am not really sure how to do so short of reflashing the firmware.
Am I missing something obvious? I know a lot of folks were recommending handwire/a total IC replacement, which I feel would be quite a bit more work than using a previously proven method to wire this keyboard up.
Let me know if I am missing any details! I have been intermittenly tinkering with this project for the last few weeks so I may have forgotten something.