Granlunds FrankenSTein

[PhilC]

@agranlund

Are you some kind of genius?

More of a mad scientist perhaps?

[agranlund]

@agranlund

Are you some kind of genius?

More of a mad scientist perhaps?

Haha yes mad scientist is probably a more accurate description
To be honest, it's far easier doing these kind of things when you don't have any regard for other users than yourself. Designing things that are supposed to work on many different machines or setups, plus are easy to use & install is a different ballgame entirely as I'm sure Exxos can attest to.

I'm mainly interested in seeing how far I can push my old ST, and learn new things while doing so. If others can somehow benefit from my schematics and/or source code then that's great

[agranlund]

Still much work left but it's a start

[exxos]

Nice!!

[agranlund]

Nice!!

Thanks!

It sure is nice to have the TF536 back in! You get so used to the responsiveness that its hard to use the machine without it

DSC_0819_2.jpg (113.19 KiB) Viewed 4116 times

(it's getting crowded inside, but there's still room for special stuff in the red area)

Attaching the TF536 exposed some issues when the gfxcard was being hammered hard from the CPU while running at a high pixel clock.
It's still not 100% stable at 1280*960 with the TF536 attached but I got it working in 1024*768 and lower after a bit of blitterboard firmware tweaking. Also had to play around with the displaymode parameters, and in the end, setting dram priority to CPU for the faster modes made a big difference.

So while it's not perfect it's at least good enough for now that I can keep the TF536 attached

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[frank.lukas]

With my Atari Mega ST4 a TF520 is work not with my STGA ET4000. The machine boobs at boottime. I tested the same config not with a PAK68/2 but I think it must work?

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[agranlund]

With my Atari Mega ST4 a TF520 is work not with my STGA ET4000. The machine boobs at boottime. I tested the same config not with a PAK68/2 but I think it must work?

I am mostly guessing now but maybe the ET4000 is really sensitive to the bus timing being exact 8Mhz, being an ISA card and all?
The VOFA documentation seem to hint at possible timing sensitivity for these cards:

Nicht funken tuts (hoffentlich momentan noch) mit:
Medusa T40, PAK-68/3 mit 68030 und mehr als 32 MHz, mehr als 8 MHz
Systemtakt auf dem Board.

I never tried the TF520 but the TF536 seems a lot better with expansions compared to the TF534.
With the TF534 I was never able to get the NetUSBee working and UltraSatan was dodgy at best, but everything just works so far with the TF536 running at 50Mhz.

Changing RAM priority to CPU did help a lot for me to get it working with the accelerator attached:

DSC_0822.JPG (93.31 KiB) Viewed 4094 times

(I'm using the driver that comes with NVDI)

[agranlund]

Hmmn.. I think the next logical step with this is to go ahead with making the blitterboard actually be the ET4000.
Getting rid of that ISA card and cable would make it a lot nicer looking inside for sure. And as a bonus it'll be much easier for anyone else that may want a gfxcard in their STM.

Not sure if this will happen before or after a very vaguely planned "STEreoids" upgrade though

[DoG]

Will your own designed AT4000AX have 1Mb, 2Mb? Can it handle 4Mb?

[agranlund]

Will your own designed AT4000AX have 1Mb, 2Mb? Can it handle 4Mb?

The reference design in the data sheet seem to imply 1MB is max for the ET4000AX (and so does the driver that comes with nvdi). I'm sure I've heard about 2MB cards for the Atari though.. maybe those were ATI Mach cards?