Playing with a PPU (UA6538)

PPU requires a clock signal input at pin 18 and for the UA6538 it must have a frequency of 26.601712 Mhz because it's a PAL chip.

I don't know what are the clock signal input specifications so I'm trying to use this simple clock generator circuit:

I'm getting just 2.2 Vpp oscillation but it seems to be ok for the PPU:

The PPU video output cannot be connectd directly to the TV low impedance AV input: we need a video buffer circuit like this one:

See you next time!

Ciao!

I'm feeling like the young doctor Frankenstein in moments like this.

I have connected all signals trying to keep the wires as short as possible:

I want to keep memory signals well separate from video out and clock generator, this is the BB main chips layout:

After giving the power supply we got a nice PAL video signal at pin 21.

This is the first PAL line:

This is the PAL line #44:

This is the last PAL line #312:

We can move on now, see you next update!

Ciao!