ZX80 CORE ROM

Discussions about Sinclair ZX80 and ZX81 Hardware
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acsi
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Location: New Zealand

ZX80 CORE ROM

Post by acsi »

Hi

So the other damage done thanks to my faulty monitor was to my ZX80 CORE. Seems to be the ROM that's been corrupted.

I have a 27C256 I can burn to replace it but can someone please advise how to make up the binary?

Thanks
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1024MAK
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Location: Looking forward to summer in Somerset, UK...

Re: ZX80 CORE ROM

Post by 1024MAK »

Do you mean Pokemon’s ZX80Core?

The manual is here ;)

Can you erase EPROMs?

Mark
acsi
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Location: New Zealand

Re: ZX80 CORE ROM

Post by acsi »

Yes I can erase eproms. The EEPROMs that I got for the kits seem to program ok but the the code inside them changes.
I've got both machines working with 27C128's programmed with just a ZX80 ROM in one and ZX81 in the other for now.
Unfortunately one of the ZXCCB cards died as well. Luckily I had a spare as I see these are no longer available?

I would like to have the ZX80 and 81 rom available via the rom selector again but can't remember how to make the file up (I did it years ago for a Dragon ROM)

My programmer is a Genius G540.
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1024MAK
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Re: ZX80 CORE ROM

Post by 1024MAK »

I can’t comment on your programmer, not having that type.

With some programmers, you can tell it at which memory location in the chip to start programming. Hence the first ‘ROM’ image can go from 0x0000 to 0x1FFFF. Then you can tell the programmer to burn the next ‘ROM’ image from 0x2000 etc.

Alternatively, if each ‘ROM’ image is exactly 8k bytes long (8192 decimal bytes), you can copy and join files using either you command line operating system, or use a suitable hex editor that has this facility.

If the ‘ROM’ image files are not exactly 8k bytes long, then you will have to pad them out with the required number of 0xFF bytes at the end. Note that this padding is not needed for the last ‘ROM’ image file, it can be any length.

Once you have your concentrated ‘ROM’ image file, your programmer should be able to burn the EPROM/EEPROM.

Mark
balford
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Re: ZX80 CORE ROM

Post by balford »

If it helps get you up and running, here's the ROM image from my ZX80Core.

ZX80 ROMs work on positions 4 and 5 of the ROM selector switch, and ZX81 ROMs are available on 2 and 6.

I've no idea of what other content is in there, it's getting on for 7 years since I built it :D
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zx80core.zip
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acsi
Posts: 24
Joined: Tue Apr 23, 2013 12:03 pm
Location: New Zealand

Re: ZX80 CORE ROM

Post by acsi »

Many thanks.
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