What are missing on this board? (48k Issue 3)

A place to discuss the ZX80's and ZX81's younger brother - the Sinclair ZX Spectrum
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AN7805
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What are missing on this board? (48k Issue 3)

Post by AN7805 »

Hi at all,

i find this 48k board.
What ar missing on this board?
The ULA is shorted to ground. Any replacement for this?

Image

Image

Thanks,

Matteo
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PokeMon
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Re: What are missing on this board? (48k Issue 3)

Post by PokeMon »

This is the ULA, upper 32k memory I think (8x TMS4532-20) and a few logic chips.
See the link here for a high resolution graphic:

https://upload.wikimedia.org/wikipedia/ ... rum_mb.jpg
Bildschirmfoto 2020-11-04 um 23.39.24.png
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AN7805
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Re: What are missing on this board? (48k Issue 3)

Post by AN7805 »

Thanks so much pokeMon.

Matt
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1024MAK
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Re: What are missing on this board? (48k Issue 3)

Post by 1024MAK »

And the aluminium heatsink for the 7805 voltage regulator is also not fitted...

Mark
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AN7805
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Re: What are missing on this board? (48k Issue 3)

Post by AN7805 »

Mark, i have it :-)
I have removed for the photo.

Thanks,

Matt
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