Arduino-USB-HID-RetroJoystickAdapter/C64_keyboard/README.md

Poor man's "Keyrah" to connect C64 keyboard to USB (for BMC64 emulator)

Building

• Solder all keyboard connector pins to Arduino Pro Micro.
• You can solder Restore key (connector pin "I") paraller to some other pin. I soldered "I" and "G" to Arduino pin A8. (this is actually not needed, because there is one free pin left). Pins I used.
• You can also connect LED of C64 to VCC/GND of Arduino. I used 220ohm resistor.

Firmware/flashing

• Download Soarer controller firmware (Soarer_Controller_v1.20_beta4.zip): https://geekhack.org/index.php?topic=50437.0 (or https://deskthority.net/workshop-f7/soarer-s-keyboard-controller-firmware-t6767.html)
• Extract /firmware/Soarer_Controller_v1.20_beta4_atmega32u4.hex from Soarer_Controller_v1.20_beta4.zip
• Install Arduino IDE
• Connect RST to GND couple of times to get Arduino Pro Micro to programming mode (notice that com-port is different in programming mode in Windows)
• Flash firmware

# old: & "C:\Program Files (x86)\Arduino\hardware\tools\avr/bin/avrdude" -C"C:\Program Files (x86)\Arduino\hardware\tools\avr/etc/avrdude.conf" -v -p m32u4 -c avr109 -P COM5 -b 57600 -U flash:w:firmware\Soarer_Controller_v1.20_beta4_atmega32u4.hex:i
# 11.2.2023:
& "$ENV:LOCALAPPDATA\Arduino15\packages\arduino\tools\avrdude\6.3.0-arduino17\bin\avrdude.exe" -C"$ENV:LOCALAPPDATA\Arduino15\packages\arduino\tools\avrdude\6.3.0-arduino17\etc\avrdude.conf" -v -p m32u4 -c avr109 -P COM9 -b 57600 -U flash:w:firmware\Soarer_Controller_v1.20_beta4_atmega32u4.hex:i

Setup

• Download config file. Check pin order to match your setup.
• Compile and upload config file to Arduino Pro Micro

.\scas C64_matrix.sc C64_matrix.bin
.\scwr C64_matrix.bin

Testing

• https://keycode.info/

Pins I used

//   Pin    Label
//   20(A)  2(D2/PD1)
//   19(B)  3(D3/PD0)
//   18(C)  4(D4/PD4)
//   17(D)  5(D5/PC6)
//   16(E)  6(D6/PD7)
//   15(F)  7(D7/PE6)
//   14(G)  8(D8/PB4)
//   13(H)  9(D9/PB5)
//   12(0)  10(D10/PB6)
//   11(1)  16(D16/PB2)
//   10(2)  14(D14/PB3)
//   9(3)   15(D15/PB1)
//   8(4)   A0(A0/PF7)
//   7(5)   A1(A1/PF6)
//   6(6)   A2(A2/PF5)
//   5(7)   A3(A3/PF4)
//   4        N/C
//   3(8)   TX(D1/PD3)
//   2        N/C
//   1(I)   8(D8/PB4)

Links

• https://geekhack.org/index.php?topic=50437.0
• https://deskthority.net/workshop-f7/soarer-s-keyboard-controller-firmware-t6767.html
• Newest I found was Soarer_Controller_v1.20_beta4.zip from 26.10.2013
• Soarer config file documentation: https://deskthority.net/download/file.php?id=8833 (Soarer_Converter_v1.12_docs.zip)
• Keynames used in config file from https://deskthority.net/download/file.php?id=8833 (Soarer_Converter_v1.12_docs.zip): /docs/codes.html
• https://www.waitingforfriday.com/wp-content/uploads/2017/01/C64_Keyboard_Schematics_PNG.png
• http://kookye.com/wp-content/uploads/2016/02/Pinout-ProMicro.jpg
• I used this as starting point: https://github.com/abzman/Keyboard-config-file/blob/master/C64_matrix.sc
• C64-emulator for Raspberry Pi 2/3: http://accentual.com/bmc64/
• For bigger matrices use Arduino Micro (24 usable IO pins) https://www.40percent.club/2017/10/green-arduino-micro.html (The largest matrix you can do with a Pro Micro with its 18 pins is 9x9, 81 keys.)

Macro without modifier key

Even though modifier key is mandatory, it can be replaced with unpressed modifiers. This writes shifted A when only a-key is pressed:

macroblock
  macro A -ALL
    SET_META LSHIFT
	PRESS A
	CLEAR_ALL
  endmacro
endblock

Issues (all issues are fixed in newer BMC64 versions)

Issue with Menu key (fixed in newer BMC64 versions)

• .crt-files doesn't work with C= + F7, so as workaround LSHIFT + F7 is F12.

Issue with shift (fixed in newer BMC64 versions)

• "+", "-", "£", "@" and "*" doesn't produce GFX-chars when shifted

"Repair" rpi_sym.vkm (1.0.9)?

• at 5 6 0 -> 5 6 8
• minus 5 3 0 -> 5 3 8
• plus 5 0 0 -> 5 0 8
• sterling 6 0 0 -> 6 0 8
• asterisk 6 1 0 -> 6 1 8

sed -i 's/5 6 0/5 6 8/g; s/5 3 0/5 3 8/g; s/5 0 0/5 0 8/g; s/6 0 0/6 0 8/g; s/6 1 0/6 1 8/g' rpi_sym.vkm