Pin 4, the 1 MHz signal, is an output from the VideoProc ((IC6). As are the 8 MHz (pin 7), 4 MHz (pin 6) and 2 MHz (pin 5) signals.
The master 16 MHz clock / oscillator is formed by IC43 and a 16 MHz crytstal. A copy of this (after some shaping circuitry) enters the VideoProc on pin 8.
I would try a VC2023 if you have one spare. Keep in mind that if you want to fit it permanently, a modification is needed otherwise the video output does not work correctly.
Mark
The master 16 MHz clock / oscillator is formed by IC43 and a 16 MHz crytstal. A copy of this (after some shaping circuitry) enters the VideoProc on pin 8.
I would try a VC2023 if you have one spare. Keep in mind that if you want to fit it permanently, a modification is needed otherwise the video output does not work correctly.
Mark
Statistics: Posted by 1024MAK — Wed Jan 08, 2025 3:13 pm