This was posted on the BasicX forum. It was posted by Tom Becker on Friday:
I have a small pile of BX-24s that I've set aside as I've suspected
that each had developed an apparently bad pin. I have surely smoked a
few processors but others, I'm sure, are fine. I grabbed one of them
today and found that logical I/O of one pin was fine but its ADC
multiplexer doesn't seem to work. I'd like to go through them all and
cull the bad from the good.
Has anyone written a thorough functional diagnostic for the BX-24?
Has anyone such a critter for the ZX-24? Can such a thing be done?
Any enlightenment will be appreciated.
Vic
Vic Fraenckel
KC2GUI
windswaytoo ATSIGN gmail DOT com
victorf wrote:Has anyone such a critter for the ZX-24? Can such a thing be done?
We have a series of tests that confirm the proper operation of various elements of the VM and, by implication, the hardware. The I/O related tests typically require some external hardware in the form of a test fixture. For example, to test the GetADC() function, a variable external voltage source is required. One could create a test fixture that uses Port C pins to control a variable external voltage source that is then applied in parallel or through a demultiplexor to each of the Port A pins, confirming that each ADC pin functions properly.