Dell C600 netinstall X11 problem

[Tom Simons]

Debian netinstall (debian-40r2-i386-netinst.iso) completed on my old
Dell Latitude C600, but after booting off the hard drive, the X11
display is screwed up.

It looks like it "starts over" twice: 1/3 & then 2/3 of the way
across, so the login field is split up.  I tried logging in anyway
(never could see any characters I typed), but it didn't work (text
console works fine, though)

Can anyone help?  I'd really like to go back to Debian, after using
Ubuntu, Knoppix, & Redhat.