UniRefresh's web site has recently vanished. Although UniRefresh can be found on other sites I don't know about Rob Muller's other files.
Anyway here's a link to the 6bitdac file -
http://www.procerus.btinternet.co.uk/6bitdac.zip
Rob actually wrote this one blind in that he didn't own a copy of the game and coded it by guessing from what I told him of the symptoms. I had found that since installing my GeForce2 I couldn't run FU anymore. Since it was a favourite game I contacted Rob about it and he produced these two files just to fix it!
You only need 6bitdac if, after running the vesa12 or noLFB program, you find the game is really dark. It works in a similar manner to the other programs though. It reports that the graphics card is unable to support 8 bit colour so the game then runs in 6bit. I can't see a difference myself but there's bound to be some degradation. I just like it bright when I'm high up in the Grob glider over France!
Here's vesa12.com too -
http://www.procerus.btinternet.co.uk/vesa12.zip
for those that want it.
Hope this gets the game working. Applying the 2.4 game patch won't do any harm either although none of the fixes in it are really stability related.
FU remains my all time favourite flight sim despite having owned many others. It's just so refreshingly simple and direct. The planes seem to have a responsiveness that's often lacking in other sims. It's a great game for unwinding after a long day...
98lite with 629K of free conventional memory in full DOS mode using QEMM 9.0 (or 628K with UMBPCI.SYS providing real mode for FastVid) with SmartDrive, CD-ROM, CuteMouse, sound support and UniRefresh all loaded high.