Raven. A homemade Atari-like computer

[agranlund]

maybe put one of the CF sockets on the back of the PCB?

That's not a bad idea! or some of the IC's maybe.

Sort of starting to work in TOS now.
Some features are still missing, and error detection + handling needs improvement for sure.

But it's really cool being able to read my old Atari disk :)



I feel I need to make Castaway able to pass-through floppy access to the host hardware now.
Then I could play Defender of the Crown, using my old original disks, on Raven :D

[Atarian Computing]

maybe put one of the CF sockets on the back of the PCB?

That's not a bad idea! or some of the IC's maybe.

Sort of starting to work in TOS now.
Some features are still missing, and error detection + handling needs improvement for sure.

But it's really cool being able to read my old Atari disk :)



I feel I need to make Castaway able to pass-through floppy access to the host hardware now.
Then I could play Defender of the Crown, using my old original disks, on Raven :D

Purely amazing! Can't wait!!!

[kodak80]

CD drives confirmed working, Floppy disks a WIP, I am going to have to change from my light filled glass case to something that can hold these drives.

This is looking great.

:cheer: :cheer: :cheer:

[LarryL]

CD drives confirmed working, Floppy disks a WIP, I am going to have to change from my light filled glass case to something that can hold these drives.

This is looking great.

:cheer: :cheer: :cheer:

Indeed!
I can recommend the Fractal Design Pop Mini RGB
There you can keep RGB and glass and have as well two 5.25 drive bays at the bottom. A magnetic panel hides these bays

IMG_4721.jpeg

IMG_4722.jpeg

[agranlund]

I think the floppy driver can be considered beta so I made it part of the release packages.
Can be found in "software/raven/drivers/fdc"

It's currently operating in read-only mode.

(I want to do more write testing before having it enabled. And also implement the formatting stuff)

[agranlund]

Added blitter support for WD90C33

Performance is quite similar to the '31 variant.
It does have a couple of extra features such as hardware accelerated lines and triangles so that could be fun adding to the driver some day.

Screenshot 2026-02-08 02-21-01.png

wd90c33.jpg

[Mikerochip]

It's almost time we had a chart!!

You've added so many different cards now :O
(Impressive!!)

[agranlund]

It's almost time we had a chart!!

You've added so many different cards now :O
(Impressive!!)

Thanks, yes some documentation about what cards do what feels appropriate :)

[Mikerochip]

Well, it was easy enough with Nova.

Either get an ET4000, and 24bit/16/15/8/4 bit DAC, or, give a kidney for a Mach32. Or two kidneys, for a Mach64 :P

I wonder, is there a possibility of back porting this to work with a standard Mega STE/TT enabled Nova machine?
I feel like a lot of ST users might benefit from, even the old crappy ISA cards.

if I could get a GD-5420 for a few quid, and it'd give me 256 colours at 800x600, I'd get one for my mATX ST :O

Even my Albert 1024x768, 4bit is a nice step up from standard resolutions, for desktop work.
(It's ... not a fast card though :( )

[agranlund]

Cirrus and WDC cards can as of now do 1280x720x8bpp :)
Tested with GD5426, GD5434, WD90C31, WD90C33. Your mileage may vary.


WDC:
These cards have physical jumpers or dip-switches to select refresh rates for the different resolutions.
You want to select 70hz for the 1024x768 resolution, in order to get 60hz @ 1280x720.

Cirrus:
Should just work, pixel clock is configurable from software so the driver does that.
I'm getting some horizontal ghosting which I cannot get rid of completely using the OSD on my monitor, so probably some tweaking still needs to be done. Could also be the mem clock not keeping up with the higher pixel clock for 1280. Not sure yet.


And in the order of fast->slow in 1280x720x8bpp
(they're all plenty fast compared to unaccelerated cards and you can't go wrong with either of them)

These are for my particular card models, there will be performance variations depending on exact brands.
Cirrus cards are easily overclocked with software but for this test they ran at stock speed as defined by the vendors vgabios.

Cirrus GD5434

gd5434.jpeg

ET4000/W32i (2MB card with memory interleave enabled)

w32i_interleaved.jpeg

Cirrus GD5426

gd5426.jpeg

ET4000/W32i (1MB card, no memory interleave)

w32i.jpeg

WD90C33

wd90c33.jpeg