What have I done wrong?

[Lardo Boffin]

I put the ceramic cap here:

[msknight]

That looks like a tantilum bead. I have a small round circle.

[msknight]

I had high hopes, but that didn't solve it.

[Lardo Boffin]

That looks like a tantilum bead. I have a small round circle.

It is just a normal ceramic cap. Not sure why it arrived in a shiny case!

[Lardo Boffin]

I had high hopes, but that didn't solve it.

I had to mess around with different values to get it to work.

[Lardo Boffin]

I think Manic Miner is pseudo hires rather than true hires.

[msknight]

That does match with me. Manic Miner worked, JB Racing didn't.

After many muttered words, desoldering the 100pF and fitting a socket, I had a 220pF and that works.

It is throwing up calibration issues with the RGBtoHDMI with the wespi either in or out, but I'll work that out.

Thanks for the help!

[Lardo Boffin]

Excellent!

It’s likely the RAM in your mod is faster than the stuff I use therefore needing the higher value cap. I think it works that way round anyway!

[1024MAK]

What is between pins 27 and 28 is code 103 and would also be a 10K resistor... being black, I think it's more likely to be a resistor rather than a capacitor... I hate SMD components

Pin 27 may have a 10kΩ connected to +5V (pin 28) because this design copies a schematic on the web. None of that affects hi-res.

OK - 33pF to 100pF cap between ground and pin 20.

I have ceramic caps. Those going to be OK? I noticed a tantilum in the picture.

Positive to pin 20, negative to ground I assume?

No need for tantalum capacitors, ceramic types are suitable. Some multilayer ceramic types may look like tantalum types.

Yes, we can't tell you what value will work because it depends on how quickly the RAM chip switches it's outputs. Too low or too high a value of capacitor and it won't work correctly.

It’s likely the RAM in your mod is faster than the stuff I use therefore needing the higher value cap. I think it works that way round anyway!

Quite

Mark