Are all Spectrum ULAs the same?
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redgatemodels
- Posts: 170
- Joined: Tue Sep 05, 2023 11:56 am
Are all Spectrum ULAs the same?
Can a ULA from say an issue 4 pcb work in an issue 2 etc?
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1024MAK
- Posts: 5118
- Joined: Mon Sep 26, 2011 10:56 am
- Location: Looking forward to summer in Somerset, UK...
Re: Are all Spectrum ULAs the same?
ULAs are backwards compatible, that is, later/newer ULA chips should work in earlier version boards.
Earlier ULA chip are not forwards compatible. However, some may work in later issue boards. The difference is mainly to do with RAM timing.
Also the ULA version is not always firmly tied to the board issue number.
Mark
Earlier ULA chip are not forwards compatible. However, some may work in later issue boards. The difference is mainly to do with RAM timing.
Also the ULA version is not always firmly tied to the board issue number.
Mark
ZX81 Variations
ZX81 Chip Pin-outs
ZX81 Video Transistor Buffer Amp
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ZX81 Chip Pin-outs
ZX81 Video Transistor Buffer Amp
Standby alert There are four lights!
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb
Looking forward to summer later in the year.