Google says the only pictures of the VGA-0021A are on this forum 😉
MMaximus posted an image of the card's BIOS ROM in the thread
u20 is the card's RAMDAC, you can see some similar cards here: http://www.vgamuseum.info/index.php/component … ic-cl-gd510-520
There's a link on that page to download a generic BIOS, which might also work for your card.
From the pictures of other cards and looking around online, it looks like either of these 2 DACs might work, but it might be worth confirming with MMaximus what RAMDAC your particular card uses. I was looking for a replacement RAMDAC for the integrated video on my Packard Bell motherboard, from looking through datasheets trying to find a replacement, there are lots of similar but different parts with varying pinouts.