What have I done wrong?

[msknight]

Manic Miner works, (which I believe is high res) but JB Racing doesn't display properly whether loaded by wespi or tzxduino. It seems to be running, but I can't see any on-screen instructions or anything.

My first suspicion is I've got something wrong somewhere with RAM or something.

[dr beep]

Real hardware?

[msknight]

Yes. Fitted with MyRetroStore internal 16k expansion

[dr beep]

Last week we had something similar but I can't find it anymore.
A capacitor was added as I recall

[msknight]

Thanks I'll try and search myself! Hopefully the post will turn up.

[msknight]

Can't find the post, although the RAM I've got does have a 10nF cap between pins 27 and 28.
https://www.ebay.co.uk/itm/256060383699

[Lardo Boffin]

I had similar issues with RAM - I had to add a capacitor to the motherboard somewhere to create a delay as the RAM was too fast to work with hires. I will see if I can find the post.

[Lardo Boffin]

Here it is:

https://www.sinclairzxworld.com/viewtop ... 332#p51332


May or may not be relevant with the 16K mod you used.

[msknight]

Thanks. I'm reading it now.

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

I'm at the bottom of page 1 of that link and am reading forward...

[msknight]

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?