Mikerochip wrote: Mon Feb 09, 2026 8:48 pm
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.
Backporting is probably not advisable since it relies on running the x86 vgabios and that's a bit of a dealbreaker on a stock 68000.
But maybe snippets of information can be usueful as reference.
One would have to make card setup and mode change code from scratch and in "bare metal" though which is far from a weekend thing.
Perhaps though, by targetting a more modern chip like the Cirrus you'll make your life easier. These are all-in-one chips with minimal external components -- much less vendor variations to support compared to something like the ET4000 that relied on external clock generator and ramdac.
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
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
Yeah the asking price for some of these cards is nuts.
Even the ET4000 feels overpriced due to popularity. They are no doubt great MS-DOS cards since they saturate the bus, but so does a bunch of others too. And all the ones in the top pack end up at near enough same framerate being bus-limited. Perhaps it just became the most well known one, or was one of the first ones to do so?
For the price of GD5420 I would probably aim for something slightly higher would I be in the realm of making some kind of driver aimed at reasonable priced cards for stock machines I think (I am not, so it's pure speculation
)
It feels like there is quite a wide span of different cards ending up at roughly the same price point. Everything from really slow ones to sometimes even fast accelerated cards.
I think I ended up paying ~30 eur for a notoriously bad Trident card (which I wanted out of nostaliga and for testing). And that's not too far off from what I bought the WD90C33 for..
The accelerated WDC cards can sometimes be had for cheap since they're not as recognised as Cirrus.
But still they are in the same ballpark as GD5426 in terms of performance.
I grabbed my WD90C33 for ~50 eur which is cheaper than a lot of unaccelerated cards. Same MS-DOS performance as ET4000 but with hardware acceleration to boot.
One can sometimes find a good price for Cirrus cards too. The GD5428 isn't as well known as the more common 26 and 29 models so can sometimes pop up for cheap. There's one on ebay right now for 65 eur or best offer which is quite a good price I think.
There's a GD5426 for 55 eur as well, but listed as a 512Kb model. It looks like it has 1MB of chips on it so perhaps some of it is broken.
Or, with luck, it could also be that the MS-DOS utility shown saying 512Kb is misstaken or that it's only true in his very specific context; running MS-DOS on his particular PC with his particular PC Bios settings etc..
(I bought an ET4000/W32i for less than usual where the seller was showing that exact same MS-DOS utility reporting it as a 512Kb card. That card had 1MB of ram chips on it and all of it was perfectly usable for me)
That GD5426 looks a bit dodgy with the writing of OK on one of the ram chips and what looks like an X drawn on the cirrus itself though.. so maybe it is just a broken 1MB card working as 512Kb.
