I'm trying to dump the firmware of the SD870 but none of the LEDs we've found so far work with the IR phototransistors I've gotten... (1 generic from radioshack, 1 taken out of an old Kensington trackball)
I know I'd have to run some kind of scanner to find it - but what kind of methods are available in the firmware to write out to the A/V jack? Would it be possible to send chirps out the A/V jack and bypass the blinkers altogether?
If it's feasible, I wouldn't mind trying to find it. I'm going to continue to scan for the AF LED - because I'm confident that one will actually give me enough signal-to-noise to get a decent dump... but... if that search continues to prove fruitless... having another thing to scan for would be worthwhile.