6300 rom BASIC ??

[Dan Wells]

While attempting to install an old modem of unknown make, I seem to have
messed up a friends 6300. During the POST it comes back with something
like 'rom BASIC unavailable Press reset to re-boot.' He says that he
has never seen this before. The computer has a 20 meg HD in it.
Right before the reboot that gave this result I had issued a DOS
shell from procomm and ran infoplus 1.00. Procomm was dispatched from
some generic menuing program. I then exited the shell and procomm and
ran telix which hung trying to initialize the modem. So, reset the 
machine, and we get this error message. The computer will boot off a
floppy, but DOS says drive C: is invalid.
Does anyone have any ideas? I really would like to get his computer
working again as he has all his customer files on the HD, with NO BACKUP!
help?

-Dan wells at uop.edu