Raven. A homemade Atari-like computer

[mrbombermillzy]

We had a very similar discussion about the whole ISA ET4000/M32/etc card scarcity problem here:

https://www.atari-forum.com/viewtopic.p ... 64#p450764

Alternative ideas were looked at. Maybe worth a quick peek?

[agranlund]

Yes Mikro made me aware of this indeed. Even these common cards are getting expensive. Will be sending him one. I hope it will work for him. It seems to be a gamble on compatibility when I understand your feedback correctly. (RAMDAC I assume..). CL is still cheap on eBay…
But Ok enough of the negative. We now want to see cool things on the Raven.

I'm seriously thinking of snatching up a couple of GD542x cards to experiment with while they're affordable.

On very positive note, at least for me.. 320x200x8bpp on Mach32




Ok, so to make this an easy iterative process it's currently switching from whatever EmuTOS built-in Mach driver had set up, and there's no turning back
There's more stuff to set and restore until it is able to switch out of, and return to, whatever setting the Nova driver is on.
And then bake it into some kind of small library with a clean API.

Still. This made me happy. I need that 320x200 resolution, and I'd hate to go back to the Et4k now that I have the M32.

[agranlund]

Took a break from the Mach32 stuff for now and did some more work improving the Nova support in SDL.

That, together with some gentle ISA timing violations bumped Dooms performance by quite a bit.

This is on the ET4000:



Xenon, at the end of the video ran too fast before as well.
Now it runs a bit faster too fast, the ST emulator needs a proper frame pacing implemented.

[mrbombermillzy]

Great progress. Doom is running plenty fast.

Xenon, at the end of the video ran too fast before as well.
Now it runs a bit faster too fast...

To be brutally honest, even remembering when it was first released (fairly early in the ST life cycle), I always thought Xenon was too slow paced.

This certainly peps it up a bit. I would leave it as it is.

Same for Ikari Warriors. I bet thats more 'challenging' on this HW.

[agranlund]

To be brutally honest, even remembering when it was first released (fairly early in the ST life cycle), I always thought Xenon was too slow paced.
This certainly peps it up a bit. I would leave it as it is.
Same for Ikari Warriors. I bet thats more 'challenging' on this HW.

I agree, playing it at correct speed nowadays feels way too slow paced.

Back then I loved it!
Defender of the Crown, Arkanoid and Xenon.. much fond memories

[Oldskool]

Really nice fps.. and I can’t play Xenon that fast
On normal speed I never got anywhere in level 2.

Are you also planning to do something with a isa soundcards (eg picogus or an old model sb).

[agranlund]

Are you also planning to do something with a isa soundcards (eg picogus or an old model sb).

Ooh, that Picogus looks really interesting! And open-source too. That's perfect. Thanks for bringing it to my attention.
I signed up on the email list to get notified when the next batch of v2 becomes available to order

I'm waiting for one of those Adlib remakes to arrive in the mail, and which I'm very much looking forward to playing around with but I know I'll need something else that is capable of playing digitized sound.

[Oldskool]

Ooh, that Picogus looks really interesting! And open-source too. That's perfect. Thanks for bringing it to my attention.
I signed up on the email list to get notified when the next batch of v2 becomes available to order

I'm waiting for one of those Adlib remakes to arrive in the mail, and which I'm very much looking forward to playing around with but I know I'll need something else that is capable of playing digitized sound.

Can send you free of charge 2 x Picogus pcb v1 (very diy friendly). Almost the same functionality as the v2 but you can use a picopi.
Also can include a snarkbarker pcb which is a sb1 clone (1 to 1) with about 60% of the parts.
Both are open source.

Both cards can give you adlib + digital sound + midi. Although the sb is mono but very oldskool and big….
Picogus emulates all the major isa soundcards from the golden age although some emulation is not yet perfect.
Gus emulation is like 99,99…

PM me for the shipment address.

One of the drawbacks for the picogus could be:

PicoGUS requires an ISA bus speed of 8.33MHz or lower. Glitchy playback or silence may happen at higher bus speeds. Also compatibility with different chipsets may vary, specifically for DMA.

IMG_1756.jpeg (418.77 KiB) Viewed 2868 times

[agranlund]

So.. that was a pleasant surprise!

mint_mp.jpg (17.92 KiB) Viewed 2745 times

I had just assumed it wouldn't work since I have a non-standard (physical) layout and was worried MiNT would trash my pmmu tree.
Turns out MiNT was already dealing with such scenarios just fine

Code: Select all

 * As there are quite different machines with a 040 (or higher) out there
 * (Falcons with Afterburner, Hades, Milan) which all have a different layout
 * of their physical memory, it's not possible to create the MMU tree for
 * memory protection from scratch; instead, the one found on startup has to
 * be copied and modified as needed.

[stephen_usher]

Nice to see the Load Average there... that's my main contribution to the MiNT kernel.