OT- ROM error?

[Koyote]

Well, 
  I'm putting together a 486/100 from spare parts I have laying around- it'll be a 
nice box 
when I'm done, but I'm having a problem.

Memory checks ok, scsi goes fine, and I get a message saying bios successfully 
started, then 
I get:

NO ROM BASIC SYTEM HALTED

Never run into this before...
(I'm using an AMI BIOS chip)

Help?
Koyote