Raven. A homemade Atari-like computer

[PhilC]

@agranlund see if these will fit, I think they will.

T224162B-28J SOJ40 (1PCS)

Not the cheapest but the 83mhz (-35ns) run at 93mhz and the ones I just fitted are 100mhz or 28ns

Got them on eBay.

[agranlund]

Ah nice, thanks for the tip!

[agranlund]

Updated release package:
https://github.com/agranlund/raven/rele ... A1.latest

Code: Select all

rom: improved generic vga compatibility
rvnova: improved generic vga compatibility
rvnova: Cirrus Logic GD5434 driver
rvbios: bootscreen

Generic VGA should now be compatible with more of the old, cheap and slow variety of cards.
Tested with the following terrible choices :)
- MX 86000FC
- Realtek RTG3105
- Trident 8900
- Trident 9000i

Bootscreen image graciously provided by @Atarian Computing

[PhilC]

Thanks @agranlund, I'll update mine before going to CL4.

[agranlund]

updated rom + rvnova.

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20251007:
rom: ensure caches enabled during vgabios calls
rvnova: remove temporary vgabios workarounds

I hadn't realised until now that caches can be disabled at the time rvnova runs.
Now, cpu caches are always enabled during x86 emulation regardless of the cache setting for TOS.
This greatly speeds up setting the initial desktop resolution on GD5434 cards.

[PhilC]

Works great with my Speedstar 64 card and has so far fixed the non booting with the overclocked 5429. Sometimes the Raven would refuse to boot as it hadn't detected the VGA Bios rom.

@agranlund What size is that boot pic btw? I've got one id like to use in its place......

Screenshot 2025-06-26 at 15.16.27.png

[LarryL]

Can’t wait, to start my own build :D

We are actually 4 fellows from Germany, sourcing boards and components together.
I think we will start building the Raven during next 4 weeks
I will then create my own „build blog“ here :mrgreen:

Cheers
Michael

[PhilC]

Can’t wait, to start my own build :D

We are actually 4 fellows from Germany, sourcing boards and components together.
I think we will start building the Raven during next 4 weeks
I will then create my own „build blog“ here :mrgreen:

Cheers
Michael

Looking forward to seeing your builds.

[agranlund]

Works great with my Speedstar 64 card and has so far fixed the non booting with the overclocked 5429. Sometimes the Raven would refuse to boot as it hadn't detected the VGA Bios rom.

@agranlund What size is that boot pic btw? I've got one id like to use in its place......

Screenshot 2025-06-26 at 15.16.27.png

Nice!
Are you able to build sw/rvbios ?

If you are, you could replace sw/rvbios/rvlogo_1bpp.bmp with your image
1) Run "make logo" to (re)generate logo.c from your updated image
2) Run "make" to build rvbios.prg
(tested on Mac, I assume it'll work on Linux too)

The current image has a size of 320x320 but your replacement image could have any size up to 640x420(*) as long as you keep the width a multiple of 8. It should be a standard 256 colour indexed windows bmp, using colour index 0 and 1 only.
(The boot resolution is technically 4bpp so I'm planning on supporting more colours for the boot screen but for now it needs to be a mono image)

Right now the image, whatever its size, will display in the center but slightly offset upward (centering around location 320,210 of the total 640x480 screen area)
As I'm typing this I realise I should put on my todo to have it always take a full 640x480 image instead.. the final data in logo.c is RLE compressed anyway so large blank areas add very little to the data size.

If you're not able to build the thing I can do it here if you want.

[PhilC]

@agranlund I should be able to build rvbios. I'll have to convert the image to a bmp, I had it as PNG or raw file.

The Raven is being troublesome at the mo, crashing under doom or Tyrian with my new graphics card and the old GD5429 2mb. The 1mb version I have seems to work fine but occasionally the screen goes black but music still plays with Tyrian.