Well there are some bad news from the tests that I and some friends did these days. UDMA works only on VIA chipsets. It doesn't work on Intel, SiS or ALi chipsets. Even on the older VIA VT82C686B south bridge there are write errors without VDS (Virtual DMA Services). Perhaps this is normal for such a hardware-specific driver like this, initially written for personal use on a single PC with the latest VIA VT8235 south bridge, on which there are no errors in neither mode. We're investigating the issues, but of course will appreciate any competent help. Meanwhile I updated all UDMA files (still version 1.3 as there are almost no code changes) at http://linux.tu-varna.acad.bg/~lig/freedos/ and will inform you on any updates.

Best wishes,
Lucho