V4SA and resolution mode

[OL]

Hello

To clarify what output is able to do V4SA on HDMI port.

Resolutions:
320x200
320x240
320x256
640x400
640x480
640x512
960x540
480x270
304x224
1280x720
640x360
800x600
1024x768
720x768
720x576
848x480
640x200
1920x1080
1280x1024
1440x900

This resolution could not be supported by all monitors I have Viewsonic monitor and all are well support without issue

Screen format:
Atari 1 plan (SThigh like)
Atari 2 plans (STid like)
Atari 4 plans (STLow like)
8 bits chuncky (different from Atari 8 planes not yet supported)
8 bits YUV (not support by NVDI)
15 bits RGB (not support by NVDI)
16 bits RGB (like Falcon)
24 bits RGB
32 bits RGB

All screen format can be used with all screen resolutions. There is no Videl like system, you can't create specific resolution
Emutos without NVDI support only ST screen format of course.
Most issue is STHigh screen format it blink a lot and can't be used for normal use, more resolution is low most it blink, other ST screen format can blink a little bit on lower resolution. This issue is known and wait a fix in FPGA, other screen format have absolutely no blink issue.
Castaway emulator for V4SA can run game in lower resolution with Atari format without blink because able to emulate screen in software (option to use direct resolution is possible but blink) You can see a video of Castaway V4SA here: http://v4sa-atari.lutece.net/video/bluesbrother.mp4

NVDI 5 support most screen formats, change resolution at fly is possible, hardware control is done in Emutos.

V4SA is more near to a clone than an Atari, we not claim full compatibility with ST or Falcon computer, register hardware of this computers are not present, we hope better support in future but it is an hope not a target, it depend highly of V4SA FPGA developers not from us.


Olivier

[shoggoth]

There's an 8bpp TT/Falcon-compatible (interleaved bitplanes) mode as well, but it's not quite working yet. There's a reserved spot for it in the video mode register though.

[Cyprian]

Most issue is STHigh screen format it blink a lot and can't be used for normal use

there could be an workaround for that - native Amiga video mode with turned dma on only for 1 bitplane

[1st1]

Hello

To clarify what output is able to do V4SA on HDMI port.

Resolutions:
...

It only makes sense if there are the ST/STE/TT/Videl compatible registers to set up these modes. Are they present that any Atari software can switch them like on legacy hardware? We all know about that crappy software which makes use of that.

[shoggoth]

No. It's got a TOS4 compatible video XBIOS.

Having some degree of hw register compatibility is possible though, even without support in the FPGA.

[1st1]

Having some degree of hw register compatibility is possible though, even without support in the FPGA.

Gunnar told me years ago (in 2016) that they want to do that. They didn't during the past 8yrs. That's one of the reasons why I am skeptical now to any announcement for more Atari compatibility of the Vamp. It won't happen.

[Gunnar68080]

I think the above list misses PAL and NTSC screenmodes which are also supported.

FYI

The V4 always included support for the Atari screen modes. Both the Atari resolutions and color modes.
The recent V4 core has both the Atari video Shifter register to display planar modes with 2 / 4 / 16 color
and the YAMAHA sound chip. Programs banging the HW register work.

[TheNameOfTheGame]

Wow, amazing Gunnar...you doing some serious magic here!

[OL]

Having some degree of hw register compatibility is possible though, even without support in the FPGA.

Gunnar told me years ago (in 2016) that they want to do that. They didn't during the past 8yrs. That's one of the reasons why I am skeptical now to any announcement for more Atari compatibility of the Vamp. It won't happen.

Of course all this is possible, there is 2 way for that, or hardware or software, this is not new, 3 days ago I will said the second one has more chance to come with a little bit help of Apolloteam because such approach have been already used in several software, very long time ago perhaps people have forget this, it was possible to have a Mac on an ST, it was name spectre and was done by Dave Small even without MMU that is totally crazy, recently run an Amiga native have been ported to Atari computer, so yes it is possible no doubt. Now today look like the first way or something between is more probable making perhaps more people happy.
I'm not nostalgic, most developer have move to 68060 and globally software are more clean, for me already this computer is fine, I never promote something that was not existing yet and sure to be working, perhaps people are frustrating for this but I don't understand why. When I receive my V4SA long time ago, hopefully someone before have work to be able boot Emutos on it, that was why I bought this computer, but it was running in B&W 320x120 so there was work and it have not been easy for the 2 first year with improve and regression. So Apolloteam has to work on the product to have a really good one, so much have been done since (FPU, speed (around by 3), 3D ...) so much.