abc806keyboardadapter

ABC 806 Keyboard adapter

This project is released under the GNU General Public License v2.

Summary

This project contains the software needed to build a USB keyboard adapter for the Luxor ABC 806 computer.

Required hardware

- [Arudino USB Host shield Uno](https://store.arduino.cc/arduino-uno-rev3) (or compatible)
- [Arudino USB Host shield USB Host shield](https://store.arduino.cc/arduino-usb-host-shield)

Required Software

- [Arudino IDE](https://www.arduino.cc/en/main/software)

While the Arduino IDE is serviceable, VS Code together with the new Arduino plugin gives a far better development experience.

Library dependencies

- [USB Host Shield Library 2.0](https://github.com/felis/USB_Host_Shield_2.0)

Pin mappings

This is how the pins should be mapped between the Arduino Uno board and the ABC 806 keyboard connector.

DIN pin     Signal      Arduino Pin
----------------------------------------------------------------
1           TxD         1
2           GnD         GND
3           RxD         0
4           TRxC        3
5           Keydown     2
6           +12v        Vin
7           Reset       Not connected

Information about the serial connection

The keyboard is connected to the B channel of the Z80 dart using an asynchronous serial connection. In addition to the serial connection the keyboard side generates a 10 khz signal as well as a keydown event, triggering an processor interrupt.

These are the setting of the serial connection:

- 650 baud
- 8 bits
- no parity
- 2 stop bits