Sinclair ZX80 / ZX81 / Z88 Forums

It surely flickers a lot, but a photo hides the problem :P z88dk_gray_zx81_mandelzoom.jpg #include <stdio.h> #include <math.h> #include <gray.h> float a,b,c,d,e,g,h,i,j; int x,y; int xmax,ymax; int k; float l,m,n,o,p; void main() { g_clg(G_WHITE); xmax=255; ymax=63; a=0.10167; //b=0.1077; b=0.105; c...

I think the best compromise is to cycle between 4 frames, a first one (light gray) appearing only 1 time and the second one (dark gray) being displayed 3 times (thus a white frame interposed only one time). The result seems plausible, observing it on EO, (this is the best screenshot I could take, th...

More about the gray library, I have 3 possibilities,: the current driver shows a first frame 2 times, a second one only for 1 time. This is in theory correct because the picture would allow a higher persistence to one of the two allowing a dark gray and a light gray. By the way the 2 frames in a ras...

Right, this makes a difference ..both?


..in the meantime I found a way to work this out:

I'm afraid it won't be healthy for your eyes !

I've already put the latest driver version online, I think it is already better than the previous ones.

Updated timing values, they look correct on EO. I'm also adding a new feature, at a very beta release level to deal with an intelaced picture, the artifacts are espected (see picture) and in this moment it gets useful to see black areas (compared to gray). Could anybody see how it looks on the real ...

While testing the new code on EO I noticed it could not work properly on 60hz sets. I don't remember how the old one was behaving, though.

I posted a "sampler" one page ago (actually it is in page #3). It includes 64rows and 8K stuff (arx64*.p).

It is good news, I suppose ? I will leave the NOP in though, so it won't stumble when run on EightyOne. I'm now trying to find a way to interlace two 64 pictures and get 4 grayscale levels (probably acceptable only on phosfor monitors, if I ever make it work). It should exist already in WRX mode. Wo...

This is DSTAR without NOPs added. dstar_crashing_on_zxpandplus.p.gz I think in my original driver I've put an even longer delay block, by the way here's the current fix wit a single NOP I'm using in the updated driver. dstar_extra_nop.p.gz They are built with the "BREAK" feature, it means that if yo...

The ROM entries I'm using at the moment: $29B - Other drivers use $29E only. Save blank lines, start NMI, POP registers and RETURN $29E - Update A', start NMI, POP registers and return to BASIC/programs $220 - PUSH register, then do VSYNC and get KEYBD $2A2 - Enable the NMI generator and return to t...