It should do, though I can't promise anything. It seems to be the only reliable driver for 'old' ati cards, and looking at the inf the x800 is listed.
Code:
"RADEON X800 PRO/GTO" = ati2mtag_R420, PCI\VEN_1002&DEV_4A49
"RADEON X800 PRO/GTO Secondary" = ati2mtag_R420, PCI\VEN_1002&DEV_4A69
"RADEON X800 Series" = ati2mtag_R420, PCI\VEN_1002&DEV_4A4B
"RADEON X800 Series " = ati2mtag_R420, PCI\VEN_1002&DEV_4A50
"RADEON X800 Series " = ati2mtag_R423, PCI\VEN_1002&DEV_5549
"RADEON X800 Series " = ati2mtag_R420, PCI\VEN_1002&DEV_4A4A
"RADEON X800 Series " = ati2mtag_R430, PCI\VEN_1002&DEV_554F
"RADEON X800 Series " = ati2mtag_R430, PCI\VEN_1002&DEV_554D
"RADEON X800 Series " = ati2mtag_R430, PCI\VEN_1002&DEV_554E
"RADEON X800 Series - Secondary" = ati2mtag_R430, PCI\VEN_1002&DEV_556D
"RADEON X800 Series -Secondary" = ati2mtag_R430, PCI\VEN_1002&DEV_556F
"RADEON X800 Series Secondary" = ati2mtag_R420, PCI\VEN_1002&DEV_4A6B
"RADEON X800 Series Secondary " = ati2mtag_R420, PCI\VEN_1002&DEV_4A70
"RADEON X800 Series Secondary " = ati2mtag_R423, PCI\VEN_1002&DEV_5569
"RADEON X800 Series Secondary " = ati2mtag_R420, PCI\VEN_1002&DEV_4A6A
"RADEON X800 Series Secondary " = ati2mtag_R430, PCI\VEN_1002&DEV_556E
"RADEON X800 XT" = ati2mtag_R423, PCI\VEN_1002&DEV_5D57
"RADEON X800 XT Platinum Edition" = ati2mtag_R423, PCI\VEN_1002&DEV_554A
"RADEON X800 XT Platinum Edition Secondary" = ati2mtag_R423, PCI\VEN_1002&DEV_556A
"RADEON X800 XT Secondary" = ati2mtag_R423, PCI\VEN_1002&DEV_5D77
"RADEON X800/X850 Series" = ati2mtag_R480, PCI\VEN_1002&DEV_5D4F
"RADEON X800/X850 Series - Secondary" = ati2mtag_R480, PCI\VEN_1002&DEV_5D6F
"RADEON X800GT " = ati2mtag_R423, PCI\VEN_1002&DEV_554B
"RADEON X800GT Secondary " = ati2mtag_R423, PCI\VEN_1002&DEV_556B
Some people have had success upgrading from 9.1 to 9.2, but it didn't work for my x1950pro.