First post here,

Recently I've become a bit of nostalgic (or rather... I was getting fed up with modern software which seems written by dummies for dummies...) and I've taken out of storage my old hardware which, surprisingly, still works after 20+ yrs of inactivity.

Last week, I've also purchased a "super" EGA card to complement an old 286 system... It's in very good shape (no scratches, no excessive sign of wear on the connectors) and I like to try some odd video modes beyond the usual ones.

It's based on the Chips & technologies 82C441/442 chipset (rasterizer+interface) which seems to be an early SVGA implementation rather than a "pure" EGA clone. To display 256 colors or output analog RGB, however, it needs an external RAMDAC, which is missing in my card. Without this extra chip, the chipset can still drive an EGA monitor (64 colors) since it has 16 internal register for the palette and the necessary ttl outputs.

The 82C441 datasheet I've found online, however, doesn't list the video modes supported (I suppose it's more a firmware thing that something baked into the chip) nor the function and settings of the DIP switches on the back (which should allow the card to interface to different monitor types). Therefore, I'm asking if somebody has seen such a card before and can provide some more info.

The card comes with 4 crystals. One is 36Mhz, thus the card supports 800x600 @56Hz. The other three are 16.257 Mhz (EGA/MDA/Herclues) 25.00 Mhz (640x480 although a little out of spec) and the last one is 26.824 MHz, which is a bit of an odd frequency. I was expecting to see a 28.6Mhz crystal for CGA emulation... I guess this board uses a different dot clock for these modes.

Here are the pictures of this board:

Any help would be welcome...