Sinclair ZX80 / ZX81 / Z88 Forums

The photo on the computing history site that you linked to shows two 4K byte EPROMs connected to the ZX80. Although granted, this was a development machine. Given that we know that the ROM code for the later ZX Spectrum was under development even after Sinclair released it (the ZX Spectrum), it is l...

My understanding is that the upgrade kit from Sinclair included a keyboard overlay and a new 8K ROM. What Sinclair called this, I can't say for certain, but my understanding is that it was the same as a ZX81 ROM. If it was not the ZX81 ROM, then can someone please point me to a binary of the special...

You talk about seeing a composite video signal. What test equipment are you using?

Mark

Hello and welcome to our forum p5s!



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Mark

Likely a lot of bots or similar. Some other forums are experiencing something similar...

Mark

Can I assume that all of these should also work with the Timex Sinclair 1000? As a TS1000 is a ZX81 with a differently labelled keyboard, screened case, different modulator and 2K internal RAM instead of 1K, yes, 16K or larger capacity RAM packs for the ZX81 should work fine with a TS1000. Mark

Pokemon has in the past made modern RAM packs, but I don't think there are any currently available.

There have also been DIY designs.

Mark

As well as the offical Sinclair 16K byte RAM pack, there was the 2K/3K/4K ZX80 RAM pack (memory size depending on how many SRAM chips were fitted in it) that would work with the ZX81. Plus many third party manufacturers that produced various RAM packs. One of the best known for more stable RAM packs...

Hello and welcome to our forum Juz571!



I hope you enjoy this forum

You are welcome to ask questions!

Mark

Glad that you are now all sorted

Mark