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AgonConsole8 / agon-mos

Official AGON QUARK Firmware for Console8: eZ80 MOS
MIT License
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Hold down shift at boot-time to skip autoexec.txt #57

Open stevesims opened 7 months ago

stevesims commented 7 months ago

Acorn systems would allow you to skip running the boot file if you held down shift at boot time. It would be nice if we could do this too.

NB this may require changes to the VDP to support this behaviour, since it is the VDP that interfaces with the keyboard.

(Acorn systems could be configured to not boot - holding shift would actually invert the boot behaviour.)

sijnstra commented 1 month ago

I've had a bit of a look at the code and was wondering if as an interim approach that didn't require VDP behaviour changes, how about reading the status of the keyboard LEDs prior to running autoexec.txt, and if <Caps lock> is lit up, don't run autoexec.txt Could even make it a think if any LED returns "on". I think there's enough time between the VDP turning on, and MOS seeking autoexec.txt to allow you to press the caps lock (or num lock or scroll lock) to prevent the EXEC. Noting that the current behaviour is to reset the status of those LEDs as part of the VDP power up sequence, so pressing any of those lock keys would be a deliberate and timed move.