Page Buffer Capture from Radius FPD/SE VRAM Input - First baby step to cloning Card

[YMK]

Wherever the full frame data or serialized input for the digital equivalent of RAMDAC on the card can be had, that's exactly what I need to feed to the FPGA.

That's more of a Rube Goldberg approach to the problem. Your card would have two framebuffers; one inside the set of antique VRAMs and the other inside of the FPGA. The GALs and VRAMs are doing nothing the FPGA couldn't do itself.

So then, what you're building is pretty much a rotating scan converter that might as well sit outside of the case.

If that's the case, you might be able to pull it off with a Pi. I think the 4 and 5 have a higher SPI throughput.

 

[Trash80toG4]

Indeed, but there would not be much interest in that, so few FPD cards available and a converter would make them more expensive. Are there other applications where a relatively low cost image rotation solution might be needed?

Implementing FPGA based rotation on a clone of the FPD Card is the only approach to big screen access for the SE I've been able to find.

Radius TPD is usable as is, via the likes of my Extron Scaler or something like RGB2HDMI(?) already, but it cannot be cloned, being ASIC limited. Later 75MHz versions of the FPD card are ASIC ridden as well. Don't know about other brands, but figuring that by the time they came out, they'd be on the CPLD/ASIC bandwagon as well. Heck, even the 512K/Plus edition of FPD is CPLD ridden. Radius 64KHz FPD SE appears to be the only path to SE GREATNESS!

I have one VidCard somewhere around here that I got because it had a cute little SE PDS adapter. It can be hooked up to some Accelerators, so I don't hold out much hope of it being clonable.

 

[YMK]

I think there might be more work involved in reverse/re-engineering this card than creating one from scratch along with a new driver, like zigzagjoe has done. You may want to ask him for his opinion.

 

[Trash80toG4]

IIRC, he's the one who told me to rework the formulas in the card's GALS as a better approach, haven't found the thread/quote yet.

I cannot do anything in the realm of driver development, much less reworking formulas in GALS,. So I'm attempting to do it in a way that I might be able to pull off for proof of concept.

Got Card, got Drivers in ROM, got INIT in hand and reverse engineering a board is within my wheelhouse . . . kinda . . . sorta . . .

If all you've got is a hammer . . . just keep bashing away at the problem!

 

[YMK]

IIRC, he's the one who told me to rework the formulas in the card's GALS as a better approach, haven't found the thread/quote yet.

Interesting. Has anyone dumped them yet? If you're just duplicating the card, I'd think it would be a straight copy, unless you're folding them into a CPLD.

 

[Trash80toG4]

Not that I know of so far, but wouldn't be surprised if @Bolle has done so already or might be willing to do so for yet another of my insane projects.

Definitely putting straight copies on the board if/when I get to that point. Have socketed GALs in hand as it is if it comes to that!