That was not just true for VGA but for many of the ...interesting... cards which were put on the market 'back in the day'. I had one of those, a 'Diamond Brand' multi-IO + Hercules + memory card without documentation or drivers I happened upon at one of the then-ubiquitous hardware dump meets - it was the 'PC Dumpdag' in Amsterdam for those who remember that phenomenon - with which I spiced up my otherwise somewhat boring Bondwell BW 32. While working on a TSR (as in 'background routine') which would make it possible to automate data entry into some school management software package I ended up flipping a bit on the 6845 display controller on the thing upon which the vertical resolution suddenly doubled. Instead of 80 columns 25 lines it now displayed a somewhat compressed and initially messed up 80x50. Experimenting further I got it up to 80x70 and 132x70. I made another TSR to enable mode switching and used this quite a lot when working in Wordperfect and the like. It also did double the normal (720x348) graphics resolution which I got to work in a few programs but which was less useable than the text modes. I tested this program on many other boards but never found another one where it worked, alas.