VDP Tests

[r57shell]

Because no one wants to answer my questions...
I'm developing testing rom, to make fast checks of vdp emulation.

WARNING: use this rom at your own risk. Only if you crazy. Mindless, or if you don't care.
It is rapidly changes the display mode. I don't know what will be with MD.

I'm not sure about right VDP behavior, so It's needs approval.
Here it is: http://elektropage.ru/r57shell/vdp_tests.bin

About last two tests: is it works same on hardware as is in Kega Fusion or RetroArch?

Interesting note: first test always crash BizHawk if you start rewind.

Update: one test fixed, one test added.

[Stef]

I don't think that no ones want, but probably that no ones know !
Did you tested your test rom on real hardware ?

[r57shell]

I didn't because I сan't do that
And, I don't recomend to do that.

[r57shell]

Updated.

Hmm blink test works only in MESS.
Strange behavior for new test in RetroArch, Kega and MESS. You can hide all sprites in link sequence if they under (after) shadow/highlight sprite.

I have more ideas..

May be create "safe" rom with safe tests only?

[Ti_]

WARNING: use this rom at your own risk. Only if you crazy. Mindless, or if you don't care.
It is rapidly changes the display mode. I don't know what will be with MD.

Sounds evil.
This may be used against pirates.

[Stef]

Honestly i'm not sure you can damage your MD by simply writting to registers, even incorrect values / too quickly or whatever.
But i guess because of internal hardware timing stuff it won't behave as expected.

[r57shell]

Honestly i'm not sure you can damage your MD by simply writting to registers, even incorrect values / too quickly or whatever.

Ok, then test it I think it can do some overheating, if changes of display is not simple. If it isn't so, then everything will be fine.

But i guess because of internal hardware timing stuff it won't behave as expected.

It is target of research . And... by the way, I'm making changes maximum two times during VBLANK ON/OFF cycle. So, it is not so fast.

[TmEE co.(TM)]

There won't be damage to hardware in any case, not the MD. But a typical TV is likely going to lose synchronisation for a bit when resolution changes.

[greatkreator]

nothing special happens even if you change the mode each "clock".
just incorrect work. actually nothing could happen.

[r57shell]

It's nice, but no results so far. I mean noone post results/screenshots so far.

[greatkreator]

"move along there is nothing to see here"
in that place (where everything is devastated) the cell mode is changed almost each clock (at least such change "ordered"). how fast it is actually executed I don't know.

[r57shell]

even if you don't see screen, you can change tests by arrows keys on pad.
as far as I can see, you're using LCD, so it's not what I need actually for those fast mode-change tests. Anyway thanks, at least now I know how it looks like on LCD, but anyway, say what test it is (first or some other one?)

[greatkreator]

I can make CRT test as well if it does matter.

[r57shell]

Reason why picture from LCD does not really represent actual data,because composite signal made for CRT, and when LCD does decoding, noone knows what assumptions and bugs it has.
CRT will show how it actually looks.
But, results of tests should now be just some pics... it should describe behavior of each test.
in last ones there are some settings, that tests many things, and some tests in the end allows to make easy visible how works VDP highlight/shadow priority stuff, depending on color index, priority, layers order and color itself.

I'll add some more tests in case if there will be interest.

[MrTamk1s]

In the name of science, I captured a video of all of the tests on a Big CRT from a VCR+DVD combo. In case it matters, I recorded the tests from a MD2 VA 1.8+32x VA0 for quality. This MD2 has a Sega 315-5708-01 ASIC for the VDP. No hardware blew up . Interestingly, VDP Redraw Test #4 acted differently on my smaller CRT and on the Big CRT. On the smaller, the screen completely rolled over, while on the larger, only the first few rows were flickering/rolling.

Any particular combinations for the VDP Color tests for me to try on the CRT, let me know