This document is intended to explain how to use Ultra-DMA aka Ultra-ATA aka Ultra33 hard drives and controllers with Linux. In some cases there is no difficulty in using them, but some tweaking can increase performance. In other cases, you need to go to extraordinary lengths simply to access your hard drives.
The information in this is document is, to the best of my knowledge, correct, and should work. However, there may be typos, there may be mysterious transmission errors, and there may be strange incompatibilities within your own system that prevent the techniques described herein from working properly. So... before you go fiddling around with you hard drive, BACK UP ANY DATA YOU WANT TO KEEP!
Brion Vibber (brion@pobox.com) - The document itself
Gadi Oxman (gadio@netvision.net.il) - The Promise Ultra33 patch & finding the secret numbers for the workaround
John G. (prefect@ipass.net) - VIA VP2 patch & info
Giovanni (giovanni@sudfr.com) - UDMA-enabled VIA-related patch & more info
Martin Gaitan - Promise ide0/ide1 workaround
Norman Jacobowitz - Bugged me to add info on the VP3
v1.3, 5 March 1998: VIA VP3 info, better patching instructions, pointer to more recent Promise patch.
v1.2, 27 January 1998: Additional Promise workaround info.
v1.1, 21 January 1998: New info about VIA chipset, installing around the Promise Ultra33, and enabling Bus Master & UDMA transfer modes.
v1.0, 19 January 1998: More or less complete, first version done in SGML.