Enhanced ARX True High Resolution Display Driver

[Moggy]

I have a UDG4ZXpand board and can test if needed.

[Moggy]

On real zeddy with UDG4ZXpand set for 64 mode Stefano's programs either crash or those that run have spurious dots and lines here and there, 128 mode makes it worse although the eagle one seems OK.

ARX is working well enough in Kmurta's Forth79 if that helps.

[stefano]

Ok, I'm trying to merge in the Paul's code, but honestly I'm doing it mechanically, replacing the existing code portions with the new ones.
I haven't identified the code changes permitting the better control of the picture sync, and the 64 rows mode is temporairly lost (on my prototype) but it is sort of working.
I'm still getting the character roll effect though, now also without the ZXpand+ emulation enabled.

zx81_arx_bug.png (9.18 KiB) Viewed 492 times

I'm trying to switch from a trial-and-error approach to something more scientific.

EDIT: GOT IT !

IN A,($FE) ; 11 Force the LNCTR to 0 aligned with the start of the hardware HSync pulse. Also sets the video output to black.

[stefano]

Yet another prototype. Am I getting closer?

arxtest_192.zip

(9 KiB) Downloaded 21 times

[Moggy]

Will test this tonight and report back.

[Moggy]

Works with UDG4ZXpand using 64 chr mode, see picture, also a picture of it using 128 chr mode.

[stefano]

Thank you. Could you test both the programs? They seem identical but one of the two includes a break keys detection

[stefano]

I'm also wondering what the 128 char mode is.

[stefano]

While testing the new driver I noticed that DSTAR crashes in 192 rows mode unless I add at least one NOP instruction.
I'm not sure whether the crash is caused by a memory alignment problem or timing/sync issues, other programs run smoothly on EO.

[stefano]

While compiling test programs I thought a sampler archive was a nice thing to have

arx_sampler.zip

(150.85 KiB) Downloaded 25 times

EDIT: 2 more teasers I got having fun during the tests.

arx-lena.p.gz

(6.62 KiB) Downloaded 17 times

arx-orbits.p.gz

(5.82 KiB) Downloaded 17 times

arx-kaleido.p.gz

(2.93 KiB) Downloaded 17 times

arx-carpet.p.gz

(1.96 KiB) Downloaded 15 times