384 rows super HRG

[stefano]

Wonderful!

[siggi]

Your screenshot seems not to match Stefano's.

That is the differene of AI (artificial incompetence) versus reality

[stefano]

I took a photo with my phone while the picture was being generated on EO.
Then I cut a portion of it, but the result is what I was hoping to get.

M1NOT shouldn't be necessary. In theory a 32K RAM expansion capable of wrx graphics should work.

[stefano]

I don't remember whether I placed the display buffer at 32768. It's a 12k blob, it overflows easily.

[stefano]

Your screenshot seems not to match Stefano's.

That is the differene of AI (artificial incompetence) versus reality

Well, yes.
You are both right, I haven't considered the phase. I have no way to predict whether the TV display will be drawing the even or the odd lines series when the driver boots.
The picture taken by siggi shows the lines in the wrong order. I'll post a new test program soon, but I'm willing to try increasing also the horizontal resolution, first.

EDIT: no luck.
I'm attacching the new test program. After the lines being drawn press 'p' to rephase (press it many times, every time you have 50% of probability to hook the correct phase).
I'm evaluating whether to add a function to invert the phase.

test_wrxi_2.p

(2.92 KiB) Downloaded 8 times

The position of the graphics D-FILE is at 32768, I still can't think at a reason for this program failing on a ZX81 with a WRX modded 32K.

[siggi]

I used a LCD monitor and an old CRT TV.
Pressing p did change the pic seen on the monitor, but the upper right faces still look ugly.
On CRT, the left upper circle flickers, but not on LCD

[siggi]

A different ZXNU and LCD:
left circle flickers like on CRT

[stefano]

Flickering is expected, the overall rate drops to 50%
The top-right face IS blurred, it is just a fancy useless experiment.

The top-left face is drawn on a single frame only, the bottom-right is drawn on both the frames and sould appear in standard 256x192 resolution as the top row.

The only real element in high resolution is the lower diagonal line. Pressing 'P' it should change slightly and gain a little bit of definition when the right phase is locked.
What I need to know is whether this line is acceptable, compared to the upper one.
I know it flickers, but basing on the pictures I think it is worth to go ahead and provide a whole graphics functions set.

In the meantime I'm still attempting to get a regular display driver (no interlace) with an average resolution, say 288 horizontal pixels but I don't think I will succeed: code timing is very critical.
Increasing the rows just a little more is not difficult but the code would slow down significantly.

Another possible trick could be to shrink the picture making it interlaced and keep the same resolution of a WRX frame. It will look ugly and will cover only the top-half of the screen but the code will run faster on the same graphics resolution

[siggi]

Ok, only the diagonal lower line: looks good:

And now: bad:

[stefano]

test_wrxi_3.p

(2.93 KiB) Downloaded 7 times

New version. I tried to mockup a theorical high resolution face symbol.
I also removed the blurred picture, it now shows the flickering/ghosting picture (almost the worst case scenario of a single frame in use).

It is good to know that on some LCD display the picture is reasonably stable, though.

Siggi, don't get crazy testing everyting, I think your feedback is already rather good.
I'm mostly concerned for the crash reported by Moggy, I suppose the ZXpand provides 32K, it shouldn't crash.