Reversible 16K RAM

Discussions about Sinclair ZX80 and ZX81 Hardware
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XavSnap
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Re: Reversible 16K RAM

Post by XavSnap »

McKlaud wrote:A10 line is connected via L2 (link) to the new memory chip.
Yes, you had to connect the L2 bridge.
Xavier
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1024MAK
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Re: Reversible 16K RAM

Post by 1024MAK »

A different method (cutting tracks on the PCB) is shown here (the advantage being you can use plug in a new RAM chip without having to mess about with wires on some of the pins).
This site shows details of all the extra connections including the link wire.

Mark
Trevor_B
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Re: Reversible 16K RAM

Post by Trevor_B »

Did anyone take a copy of Dave C's blog post for this upgrade? It looks like Dave's taken down his blog due to ongoing requests - which leaves me in the lurch as I was going to do this upgrade at the weekend now the Ram chip has arrived.

I know there's some more "permanent" versions available but I really don't want to cut any tracks; it's very unlikely that it'd ever be reversed anyway, but I'd prefer an option, just in case of problems.

Trevor
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1024MAK
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Re: Reversible 16K RAM

Post by 1024MAK »

It’s slow to load, but there is an archived copy here.

Mark
Trevor_B
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Re: Reversible 16K RAM

Post by Trevor_B »

Thanks very much Mark - much appreciated.

I've now got a PDF version stored so hopefully it'll all be good.

Once again - thanks

Trevor
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Re: Reversible 16K RAM

Post by 1024MAK »

If you have any questions about this or any other 16K internal RAM modification, please ask.

Mark
Trevor_B
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Re: Reversible 16K RAM

Post by Trevor_B »

Not the greatest start today - thought I'd make sure the machine was working before upgrading, only to find the 20+ year old telly I'd recently bought for it's analog tuning doesn't actually have an aerial socket. So - I'm going to take the zx8-ccb route initially ( I have one) - just to make sure things work then I'll do the upgrade. A minor setback - I just ran out of time due to other family "stuff".
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