seeking 800x600 resolution using XFree86 on IBM Thinkpad 570

[Norman Ramsey]

Has anybody actually succeeded in getting 800x600 resolution on
a Thinkpad 570, using XFree86 3.3 or greater?  Using shift-NumLock
does not enable the keypad + as claimed, and I have not been able
to find an 800x600 mode for my XF86Config that actually works.
Any help would be appreciated.

(In case you are wondering, I need this to drive brain-dead VGA projectors.
For this purpose, even 640x480 would serve.  I know the modes are out
there because Windows can find them...)

Norman Ramsey