Sinclair ZX80 / ZX81 / Z88 Forums

So the conversion of the classic HERO for ZX 81 by Nocash runs fine on the NO$ZX emulator from Nocash themselves but if I try to run it on ZEsarUX or EightyOne I get a rolling screen, this GIF is a capture of what I'm seeing.



With EightyOne I can change the vertical hold in the TV emulation to stabilise the picture, but I haven't found any option in ZEsarUX that has any effect.
Does anyone know what this happens? Does this same effect occur on a real ZX81?
No other game I've tried does this, even other WRX hi-res games from Nocash like Beamrider.
Is there any way around it on ZEsarUX too?

It's not the ZX81, it's the TV, or in the case of emulators, the emulated TV. Hi-res games alter the video signal timing, and if the timing is far enough off, on a physical TV you have to adjust the vertical hold to compensate

As David says, HERO generates a TV signal that is out of bounds for some TVs. I have to adjust the emulated TV settings in picozx81 to get a stable image.

sharopolis wrote: ↑Tue Apr 22, 2025 4:15 pm No other game I've tried does this, even other WRX hi-res games from Nocash like Beamrider.

There are a few programs that generate strange displays. A couple of classic ones are QS Defenda and Nova2005.

http://www.zx81stuff.org.uk/zx81/tape/QSDefenda
and
http://web.archive.org/web/201703091715 ... NOVA2005.p