The colours are not fix! You can modify them to your preferred settings but you need to change some values of the Atmel 2313A AVR microcontroller's EEPROM.
The display module can support up to eight TOS slots but for the STE only four are available. The EEPROM's space is divided into two sections:
- ring-buffer to store the last selected slot
- colour settings
Then you will recognise that the coloured frames represent four bytes each. The left-most byte is the setting for the red LEDs, next for green, then blue and lastely yellow LEDs. A value of $FF means that the LEDs of that particular colour shall be switched on, while $00 switches them off.
As you can see the Slot No.1 setting only switches on the red LEDs and so on to Slot No.4 which illuminates yellow LEDs only.
The next 16 bytes running from $60 to $6F (again framed in grey) are for Slot No.5 to Slot No.8 which aren't supported on SmartBoard STE. Leave them alone.
Then we have bytes:
- $70..$73: these (red and blue in this example) light up whenever you press DEL or BACKSPACE key while the module is in the armed state. It will reset the ring-buffer to its default state, i.e. Slot No.1 is selected.
- $74..$77: while flashing the FlashROMs you will see that the red LEDs will flash, i.e. the red LEDs are on for about 500ms then off for about 500ms. These four bytes represent the first phase of the visual flashing
- $78..$7B: this is the colour code that indicates the armed phase (red and blue here)
- $7C..$7F: these represent the colour coding for the second phase of the visual flashing and make up a pair with the colour coding at $74..$77. You can see that all LEDs are switched off.
There isn't much space in the AVR's FlashROM anymore but I would like to implement a firmware version that dims the LEDs i.e. that values $00, $01, .., $FE, $FF will represent the brightness of the LEDs.