Raven. A homemade Atari-like computer

[agranlund]

SVGA driver now has rudimentary and very work in progress support for Tseng ET4000AX and W32 cards.
Had some card laying around that wouldn't work with any of the NOVA Tx drivers, but works with this.

Was quickly put together and there are many limitations compared to the real ones:
- no hardware acceleration on w32
- no support for 16bpp or higher
- no 1280x720 yet
- 1024x768 is sketchy, my card goes to 84hz interlaced. Driver force progressive but that means 42hz which is not great but still better than interlaced which wont work on the lcd anyway.
(measuring and picking a faster clock, if available, for proper 60hz at >1024 resolutions would be next on the list of what this driver needs)

But other than that.. should hopefully just work and maybe it's of some use, or maybe not

[Mikerochip]

Great!
Hopefully useful, yeah. I've seen a bunch of cards with DACs that the Nova drivers don't cover/mention.

The ET4000 not having an integrated DAC makes life difficult, I imagine, from a driver perspective.
So, the card, really, is just a linear framebuffer? And the DAC determines how the buffer is used.
I know some of them are direct clones of others, but, going through them all must be tedious.

It also might be a fun side project, to build a DAC, and board...

Interesting approach, for higher colour counts, but, limiting, too, I presume?
The very flexibility an external DAC brings, is probably what's holding it back, for higher colour counts etc etc.

[agranlund]

Interesting approach, for higher colour counts, but, limiting, too, I presume?
The very flexibility an external DAC brings, is probably what's holding it back, for higher colour counts etc etc.

I think it's maybe just a product of that time?
Most eventually eventually ended up with chips that had everything integrated, it just took longer for some than others
For Tseng I think that time came with the ET6000

[agranlund]

Tseng fixes in SVGA driver:

Code: Select all

- Driver measures the equipped clocks as we need that info to make custom resolutions
  - 1280x720@60hz support, using CVT-RB standard for lower clock requirement (64Mhz)
     (was getting horrible "snow" on some older AX card when using standard CVT (75Mhz) )
  - replaced Tseng bios default 1024x768@84hz interlaced with 60hz progressive variant
- (W32/i/p) detect hardware variations and place LFB accordingly

That'll be it for Tseng in the generic SVGA driver for now.
It's missing bunch of stuff compared to the dedicated Nova ET4000 drivers but the basics are there.
Could be interesting to add acceleration support but at some other time.

This little side track armed me with a bit of new and useful knowledge at least.
I remember last time I worked on the S3 driver I was getting out-of-sync at 1024x768 and couldn't figure out why.. after this I'm feeling pretty confident the S3 bios might be setting an interlaced mode by default just like Tseng does.

Anyway.. Cirrus is back in again and wow its picture is so much crisper!

[Mikerochip]

Fantastic work!

Anyway.. Cirrus is back in again and wow its picture is so much crisper!

That's how I felt when I got rid of my Mach32, and replaced it with the Matrox Mystique 220
Now, that, was a fantastic card!

I had to swap it out with the Millennium II though, when I got the Voodoo II. It kept getting confused.

[agranlund]

I had to swap it out with the Millennium II though, when I got the Voodoo II. It kept getting confused.

Voodoo2.. was that still 3D only and you hooked it up to an existing 2D card? Or was that only on Voodoo1?
My first 3D accelerator was the Voodoo3. Such a huge upgrade from having played everything with software rendering up until then!


Speaking of Matrox, now this is a horrible card I wouldn't mind getting my hands on the ISA variant of:
https://www.dosdays.co.uk/topics/Manufa ... lus220.php

Perhaps the first consumer 3d accelerator (?) and probably the only one that had a version for ISA bus.
It can only do gouraud shading and has no support for texture mapping
I'm cynically assuming it's dog-slow too and I doubt there were many programs ending up supporting that card

[Mikerochip]

Voodoo2.. was that still 3D only and you hooked it up to an existing 2D card? Or was that only on Voodoo1?
My first 3D accelerator was the Voodoo3. Such a huge upgrade from having played everything with software rendering up until then!

Yeah. Offically, the Voodoo I and Voodoo II were 3D only.
(There was a Voodoo I with a 2D video card hammered on to the PCB, but, it was still a separate card, really)

The Voodoo Banshee and Voodoo 3 were the only 2D + 3D cards, officially, from what I remember.
And their silly external video cable

The Voodoo 3 must have been a massive jump.... Almost felt like travelling into the future!
I played Max Payne with mine. Got it the weekend of release, finished it in those two days.
Good times!!

I had a Voodoo 3, 3500. It was an overclocked 3000, but, had a TV tuner, and video capture.
I still have the massive big blue cable.
I miss that card a lot. Drivers were a pain, but, when it worked, it sang!

Speaking of Matrox, now this is a horrible card I wouldn't mind getting my hands on the ISA variant of:
https://www.dosdays.co.uk/topics/Manufa ... lus220.php

Perhaps the first consumer 3d accelerator (?) and probably the only one that had a version for ISA bus.
It can only do gouraud shading and has no support for texture mapping
I'm cynically assuming it's dog-slow too and I doubt there were many programs ending up supporting that card

I dunno, it might not be as bad a performer as you think.
I'm not sure I've ever seen the MGA Impression as an ISA card. VLB, sure. Not ISA though.

I see there's *some* kind of Impression, ISA, on ebay atm. two and a half grand...
Good luck fella!

Everyone absolutely slated the Mystique (220), but, that was OK.
I played Tomb Raider, and a couple of other games with it, and, while not as fast as a voodoo, it was a whole lot better than software only!

Man, I miss Matrox. (50th anniversary this year!)

I always wanted a Rainbow Runner for my Mystique 220.
Just because it was so *cool*

[luciodra]

Tseng fixes in SVGA driver:

Code: Select all

- Driver measures the equipped clocks as we need that info to make custom resolutions
  - 1280x720@60hz support, using CVT-RB standard for lower clock requirement (64Mhz)
     (was getting horrible "snow" on some older AX card when using standard CVT (75Mhz) )
  - replaced Tseng bios default 1024x768@84hz interlaced with 60hz progressive variant
- (W32/i/p) detect hardware variations and place LFB accordingly

That'll be it for Tseng in the generic SVGA driver for now.
It's missing bunch of stuff compared to the dedicated Nova ET4000 drivers but the basics are there.
Could be interesting to add acceleration support but at some other time.

This little side track armed me with a bit of new and useful knowledge at least.
I remember last time I worked on the S3 driver I was getting out-of-sync at 1024x768 and couldn't figure out why.. after this I'm feeling pretty confident the S3 bios might be setting an interlaced mode by default just like Tseng does.

Anyway.. Cirrus is back in again and wow its picture is so much crisper!

Now my ET4000AX T0 somehow works with 256 colors without artifacts, but something is still missing...

[agranlund]

Now accelerating v_bar primitives.
That VDI Graphics test is including lines and circles which are not accelerated.

after.jpeg (90.24 KiB) Viewed 780 times

was

before.jpeg (85.07 KiB) Viewed 780 times

[Mikerochip]

Instead of nVDI, would SpeedoGDOS be useful?
At least it wouldn't slow down the video cards...
Or, one of the other GDOS replacements.
(Which I've never used!)

TTF-GDOS etc. https://sourceforge.net/projects/ttf-gdos/