noshutdown wrote on 2022-08-09, 04:32:

i am trying to identify a picture of a slightly unique trident8900c card. while most 8900c cards came with dip 8bit ramdacs that supported up to 256 colors, this one has a plcc-44 ramdac from bt. unfortunately the picture is pretty blurry so i could only see the "bt" trademark, but not the exact model.
can anyone give me some info on which model it could be so i can find whether it supports high/truecolor?

BT481 and BT482 spring to mind . See https://datasheetspdf.com/pdf-file/1145420/Brooktree/BT482/1

darry wrote on 2022-08-09, 05:37:

BT481 and BT482 spring to mind . See https://datasheetspdf.com/pdf-file/1145420/Brooktree/BT482/1

i am disappointed because, from the blurry picture i can barely tell that the first two digits read "47X", and i think all 47X models are 256 colors only.
so far i've only seen trident8900d cards with tkd8001 ramdac supports high/true colors, all prior models(8900b, c, cl, cl-c) seemed to be only equipped with 256color ramdacs.

Forgive me if I am being intrusive, but are you specifically looking for a TVGA8900 variant that has Highcolor/Truecolor support or is your search more along the lines of an "ISA card with Highcolor/Truecolor support" and the the specific card you mentioned seems like it might be appropriate and be reasonably priced ?

I used to have a rev B (AFAICR) TVGA8900 variant with 1MB of RAM and only 256 color support in 1992-1994 on a cacheless 386DX-25. That card was slow as it was in 256 colors, so I doubt having any better color options would have been of much use, except maybe in picture viewers or paint programs .

TVGA8900 rev D chips are apparently much faster than their predecessors .

darry wrote on 2022-08-10, 04:08:

Forgive me if I am being intrusive, but are you specifically looking for a TVGA8900 variant that has Highcolor/Truecolor support or is your search more along the lines of an "ISA card with Highcolor/Truecolor support" and the the specific card you mentioned seems like it might be appropriate and be reasonably priced ?

I used to have a rev B (AFAICR) TVGA8900 variant with 1MB of RAM and only 256 color support in 1992-1994 on a cacheless 386DX-25. That card was slow as it was in 256 colors, so I doubt having any better color options would have been of much use, except maybe in picture viewers or paint programs .

TVGA8900 rev D chips are apparently much faster than their predecessors .

yeah i would say that i am searching for both ideas. from what i saw in the years, i reckon that only some 8900d cards are equipped with tkd8001 ramdac to support high/true color, all previous models are 256colors only.
i also feel that all high/true color isa cards are among the fastest ones: cirrus, et4000, wd, s3, ati mach and so on. i havn't seen a slow card with high/true color yet, maybe the ati wonder xl but its quite rare to find. the trident9000i is very slow and has integrated high color ramdac, but it can only support 512kb of ram so its limited to 640*400*64k. however, i seem to have seen a 9000i3 with 1mb ram at vgamuseum...

Wait...the 9000i can do hi-colour at 640x400? I'd love to see that in action.

Anonymous Coward wrote on 2022-10-07, 09:32:

Wait...the 9000i can do hi-colour at 640x400? I'd love to see that in action.

i got it wrong, its some 9000c cards paired with external tkd8001 ramdac that can do high color at 640*400, the 9000i seems to have only 256 colors integrated ramdac.

I remember reading even in the mid 90's that the 9000i had a high colour integrated RAMDAC, but my friend and I never found any video modes in which to use it.

Anonymous Coward wrote on 2022-10-07, 10:46:

I remember reading even in the mid 90's that the 9000i had a high colour integrated RAMDAC, but my friend and I never found any video modes in which to use it.

i read the datasheets some time before, and 9000c can be paired with tkd8001 external ramdac to support 640*400*16bit colors, 9000i only mentioned 256 color modes.