Reply To: No Sync Intellivision

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#36000
FredK
Participant

Thanks. I checked the schematics out. I’m a little disappointed that the TVP7002 IC is so finicky. I tried to see if it would sync off from the composite signal from the intellivision before it goes into the RF modulator and it doesn’t like that signal either. The sync signals from the intellivsion seem to be missing a few Horizontal pulses before and after the Vertical blanking and during the vertical blanking. For every other device I have ever seen this is not an issue, but apparently it is for the TVP7002. I don’t have a composite mod on my Intellivision so there is a small chance the signal voltage was off. If someone has a composite mod can you hook it to the sync on green and see if it brings the OSSC to life? I suspect it won’t, but be nice to rule it out.

So unless I am missing something I think it is because of these missing sync pulses, if so The only way to make horizontal and vertical signals the TVP7002 would like is to start with the clock signal 3.57mhz and try to divide it down into the correct timing. We’d need to sync that with the RGB output somehow so the clock dividers would have to look at another signal from the Inty to reference the timing with.

Fred