not sure if this is still being worked on or even taking requests any more but i know lots of arcade enthusiasts would love to have the ability to force their card to output 15khz frequency rate to help drive their old arcade monitors.
ultimarc sells these dinky rv630 based cards that can run 15khz for nearly 100 dollars.
http://www.ultimarc.com/JShopServer/...05d7080be03118