qmk_firmware/keyboards/converter/xt_usb/README.md

XT to USB keyboard converter

This is a port of TMK's converter/xt_usb to QMK.

This firmware converts XT keyboard protocol to USB.(It supports Scan Code Set 1.)

Connect Wires

1. Connect Vcc and GND.
2. Connect Clock and Data line. Clock is on PD1, Data on PD0 by default. And optionally you can use PB7 for Reset.(Compatible to Soarer's converter) To change pin configuration edit config.h.
3. You need pull-up resistor. 1K-10K Ohm will be OK.

XT keyboard protocol resource

https://github.com/tmk/tmk_keyboard/wiki/IBM-PC-XT-Keyboard-Protocol