Initially, an article stated that pin 1 of UG6 was the correct location to
find the pixel clock (according to the engineer who designed the logic
board). Soon thereafter, Kodak recommended pin 1 of UG7.
A copy of the Macintosh SE/30 logic board schematics showed that both pin
1 of UG6 and pin 1 of UG7 are tied together and generate the same signal.
In fact, several chips on the logic board, beside UG6 and UG7, generate
the pixel clock signal. Engineers confirmed this with a continuity meter
and verified a connection between pin 1 of UG6 and pin 1 of UG7. An
oscilloscope also verified that the signals were identical.
Tech Comm engineers obtained a Kodak DataShow unit and successfully
installed it on pin 1 of UG6 and pin 1 of UG7. Perhaps other factors
caused the unsuccessful installations of the DataShow unit on UG6 and UG7.
For example, perhaps pin 1 and pin 2 were shorted together. It is also
possible that a good connection was not made between pin 1 and the
DataShow interface.
Recommendation: Use pin 1 of UG7. This is for two reasons:
1) Pin 1 of UG7 is what Kodak recommends.
2) It is easier to install the DataShow connector on pin 1 of UG7.