ZX81, ARX graphics news

ZX80, ZX 81, ZX Spectrum, TS2068 and other clones
Post Reply
stefano
Well known member
Posts: 2175
Joined: Mon Jul 16, 2007 7:39 pm

ZX81, ARX graphics news

Post by stefano »

Paul just informed me that he revised the core logic of the ARX high resolution trick.

https://www.sinclairzxworld.com/viewtop ... f=6&t=5448

At the moment I'm keeping it in my to-do list. :)
stefano
Well known member
Posts: 2175
Joined: Mon Jul 16, 2007 7:39 pm

Re: ZX81, ARX graphics news

Post by stefano »

I'm proposing a quick fix, let's see if it works, it does on EightyOne.
It skips the ROM call to check the break keys and gets the value from the I/o port directly. It is slightly faster and seems enough for the problem to disappear. It also fixes the break check failing on v1 ROMs. I should do the same on the wrx part but wouldn't want to alter the display generation timing too much.
stefano
Well known member
Posts: 2175
Joined: Mon Jul 16, 2007 7:39 pm

Re: ZX81, ARX graphics news

Post by stefano »

the quick fix did not work, but we should be close now
stefano
Well known member
Posts: 2175
Joined: Mon Jul 16, 2007 7:39 pm

Re: ZX81, ARX graphics news

Post by stefano »

Image

..a bonus result, grayscale graphics in arx mode (untested) and improved grayscale in wrx mode (untested).

EightyOne shows an horizontal alignment problem which could be not existing on the real machine.
the picture flickers a lot (taking a photo is a good workaround) , but I think that on high persistence monitors it could give interesting results,
Post Reply