Not Atari, but definitely 8bit (ZX81)

Any 8bit repairs, images, cool things, upgrades etc.
Petari
Posts: 452
Joined: Tue Nov 28, 2017 1:32 pm

Re: Not Atari, but definitely 8bit (ZX81)

Post by Petari » Tue Aug 07, 2018 7:55 am

IngoQ wrote:
Tue Aug 07, 2018 7:02 am
While you're at it, check the 5V Regulator, these things were not very reliable. In my Speccy 128k I have replaced the 7805 with a L78S05CV, which allows more current and is cooler at the same time. My "toastrack" is now only a handwarmer ;)
...
I don't think that it is possible that some other voltage regulator is cooler with same load and same input voltage. Unless it works in switching mode. What is for sure not case with L78S05CV - what is "linear voltage regulator" - see data sheets. Actually, it would be hard to make switching one without coil, so hybrid technology - and much bigger price. There are some rules of physics what dictate how much heat will be produced.
There is 2 kind of people: one thinking about moving to Mars after here becomes too bad, the others thinking about how to keep this planet habitable.

stephen_usher
Posts: 118
Joined: Mon Nov 13, 2017 7:19 pm
Location: Oxford, UK.
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Re: Not Atari, but definitely 8bit (ZX81)

Post by stephen_usher » Tue Aug 07, 2018 8:12 am

PeteW wrote:
Mon Aug 06, 2018 9:05 pm
Looks like it's from late 1982 - the programming guide is a 1982 print and the software catalogue is the December 1982 edition. Is that a late model? I'll be honest I know little to nothing about the zx81 at this time!
Yes, that's just about the time Sinclair stopped selling them. The price drop shown on the box was probably to shift the last of the stock.

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