What have I done wrong?
What have I done wrong?
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.
My first suspicion is I've got something wrong somewhere with RAM or something.
All that I've learned - https://msknight.com/bbc/index.html#zx81
Re: What have I done wrong?
Real hardware?
Re: What have I done wrong?
Yes. Fitted with MyRetroStore internal 16k expansion
All that I've learned - https://msknight.com/bbc/index.html#zx81
Re: What have I done wrong?
Last week we had something similar but I can't find it anymore.
A capacitor was added as I recall
A capacitor was added as I recall
Re: What have I done wrong?
Thanks I'll try and search myself! Hopefully the post will turn up.
All that I've learned - https://msknight.com/bbc/index.html#zx81
Re: What have I done wrong?
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
https://www.ebay.co.uk/itm/256060383699
All that I've learned - https://msknight.com/bbc/index.html#zx81
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- Posts: 2173
- Joined: Sat Nov 26, 2016 2:42 am
Re: What have I done wrong?
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.
ZX80
ZX81 iss 1 (bugged ROM, kludge fix, normal, rebuilt)
TS 1000 iss 3, ZXPand AY and +, ZX8-CCB, ZX-KDLX & ChromaSCART
Tatung 81 + Wespi
TS 1500 & 2000
Spectrum 16k (iss 1 s/n 862)
Spectrum 48ks plus a DIVMMC future and SPECTRA
ZX81 iss 1 (bugged ROM, kludge fix, normal, rebuilt)
TS 1000 iss 3, ZXPand AY and +, ZX8-CCB, ZX-KDLX & ChromaSCART
Tatung 81 + Wespi
TS 1500 & 2000
Spectrum 16k (iss 1 s/n 862)
Spectrum 48ks plus a DIVMMC future and SPECTRA
-
- Posts: 2173
- Joined: Sat Nov 26, 2016 2:42 am
Re: What have I done wrong?
Here it is:
https://www.sinclairzxworld.com/viewtop ... 332#p51332
May or may not be relevant with the 16K mod you used.
https://www.sinclairzxworld.com/viewtop ... 332#p51332
May or may not be relevant with the 16K mod you used.
ZX80
ZX81 iss 1 (bugged ROM, kludge fix, normal, rebuilt)
TS 1000 iss 3, ZXPand AY and +, ZX8-CCB, ZX-KDLX & ChromaSCART
Tatung 81 + Wespi
TS 1500 & 2000
Spectrum 16k (iss 1 s/n 862)
Spectrum 48ks plus a DIVMMC future and SPECTRA
ZX81 iss 1 (bugged ROM, kludge fix, normal, rebuilt)
TS 1000 iss 3, ZXPand AY and +, ZX8-CCB, ZX-KDLX & ChromaSCART
Tatung 81 + Wespi
TS 1500 & 2000
Spectrum 16k (iss 1 s/n 862)
Spectrum 48ks plus a DIVMMC future and SPECTRA
Re: What have I done wrong?
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...
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...
All that I've learned - https://msknight.com/bbc/index.html#zx81
Re: What have I done wrong?
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?
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?
All that I've learned - https://msknight.com/bbc/index.html#zx81