Sinclair ZX80 / ZX81 / Z88 Forums

Hi there.

Minas, the coder of "Rezurection" told me an interesting thing.
He said that unexpanded ZX-81 doesn't need any modifications to display HI-RES graphic.

As You know, most HI-RES stuff requires a special modification, when we use ZX-81 16Kb.
But lately I had some troubles loading "Resurection" for 1Kb machines into real hardware ( http://www.scene.org/file_dl.php?url=ft ... &id=203282 )

Therefore Bodo Wenzel kindly agreed to make a version for 16K expansion ( http://zx81.republika.pl/rezurrection.zip )

Then I noticed that Bodo's version surely doesn't work on ZX-81 16K without HI-RES modification.
Minas replied:

"OK, that file is the version that Bodo Wenzel modified - not my original. My original is a 5-part intro for 1k ZX81, and it does not (and I really mean not) support rampacks or extensions of any kind. It will only run on original european 1k ZX81 machines. The hi-res modification is only required for rampacks, without a rampack the weird refresh-read wiring is already present on the mainboard - i.e. the 1k machine is already hi-res enabled by default. "

I'm very interested in the problem: can anybody confirm that ZX-81 1Kb doesn't require ANY hardware modifications to display sophisticated HI-RES graphic?

Greetings,
Yerz

Hi Yerz

This is all correct. I haven't had any zeddie hardware powered up for a few months now - but I'm getting the old urge again When I do I'll verify this for you.

I'm getting urges because I've developed a software MMC-card simulation (emulation implies it's correct ;¬) and wired this into EO. This enables me to play with my MMC driver code in the warm fuzzy environment of the PC. I have new plans - a hacked ROM. But that's another posting

Ha. Many thanx for cofnirming the info.
Most shocking news for me, I must admit.
Seems like theoretically ZX81 1Kb has better possibilities that ZX81 16Kb, hehe.

I wonder why is that. I mean - does the 16K interface "blocking" somehow the hi-res outptut...? Hm.

check out this article on the subject:

http://www.user.dccnet.com/wrigter/inde ... khires.htm

cheers

wilf

Hi there,

that's very interesting,
thanx!!

Y