Belatedly realised these FX codes on the Electron activate the top row of the 14B's buttons, but not the second.Those *FX commands are specific to the BBC Micro, so you definitely don't want to use them (they write to locations in SHEILA for the 6522, which doesn't exist on the Elk). Specifically they write 112 to &FE62 and 0 to &FE60, which sets the user port direction to input on PB4 to PB6 and output on all other pins.
To do the same on an Electron with the 14B/1 in user port B, try this (which I think writes 112 to &FCB2 and 0 to &FCB0):
*FX147,178,112
*FX147,176,0
and if it's in port A, try this (which I think writes 112 to &FCB3 and 0 to &FCB1):
*FX147,179,112
*FX147,177,0
These are the Elk equivalents, but whether they will work, I have no idea. Might be worth a try, anyway!
Without the 14B/1 adaptor, P.ADVAL(0)AND1 returns 1 when a top-row button is pushed, and P.ADVAL(0)AND2 returns 2 with a second-row button.
With the 14B/1 adaptor inserted and the above FX codes input, the first row returns a 1 but the second returns 0.
Am struggling to find any info on this (as in, any BBC info that can be transposed to the Elk), and I've blindly tried riffing on the FX codes above without success.
Can I ask whether anyone has any idea of what FX codes need to be input to get the second-row buttons working, please?
Statistics: Posted by origami_camera — Thu Dec 04, 2025 8:19 am