is there an updated zx81 rom?

Anything Sinclair ZX Basic related; history, development, tips - differences between BASIC on the ZX80 and ZX81
Moggy
Posts: 3231
Joined: Wed Jun 18, 2008 2:00 pm

Re: is there an updated zx81 rom?

Post by Moggy »

There are BASIC programs for checking ROM type however the one they might not pick up on is the early Division routine bugged version fitted with a CPU mounted daughter board to rectify the deficit so you would have to open the case anyway.

There are a few topics re this subject, one such can be found here...

viewtopic.php?f=7&t=4119



As for replacements those of us who go the EPROM route usually use a a 2764 like those found on the early issue Zxpands and whilst adaptors can be had the easiest method just requires two pins bent out and two wires soldered as per the picture.

Personally speaking all my zeddies are EPROM fitted using the "Big Bang" double speed BASIC ROM code which gains its speed from re-written maths and display routines. It also does away with the annoying screen flicker when using the PAUSE command and clears the screen immediately after using SCROLL rather than the messy screen clear that happens when using the original routine.

The Big bang ROM image is also attached and the relevant thread found here...

viewtopic.php?f=5&t=2986
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Spinnetti
Posts: 253
Joined: Sat Sep 12, 2020 11:29 pm

Re: is there an updated zx81 rom?

Post by Spinnetti »

the7778 wrote: Mon Oct 14, 2019 4:26 pm so one that has a better user interface?
What user interface? The "K"? :)
Zeddy: ZX80, ZX81/ZXpand, TS1000/ZXpand, TS1500/Zxpand+
Speccy: 48k, +, +2, +3, TS2068, "Bare Metal" Pi, Next KS2, IF1/Microdrives/Vdrive/Light Gun/VGA-Joy
QL: Minerva/QL-VGA/Custom PSU
C5: 24v, LiFE battery, Disc brakes
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