I have been informed that some of the early beebs didn't have the LPSTB (Light Pen Strobe) fitted, which I guess means that they don't have the track on the circuit board.
Looking at the circuit diagram, it looks like the Analogue 15 pin connector pin 9 (the one on the same end as +5v) LPSTB connects directly to pin 19 CB2 of IC3 the System 6522 VIA, I can't even see any pull-up or pull-down resistors.
Can anyone confirm that this track was missing on any beebs?
Can anyone confirm that jumping the two pins with a simple wire would be equivalent to the normal beeb connection?
for bbc micro/electron hardware, peripherals & programming issues (NOT emulators!)
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