Editing BIOS (section)

==== Boot failure ====
On the original [[IBM PC]] and XT, if no bootable disk was found, the BIOS would try to start [[IBM BASIC|ROM BASIC]] with the interrupt call to [[BIOS interrupt call#INT 18h: execute BASIC|interrupt 18h]]. Since few programs used BASIC in ROM, clone PC makers left it out; then a computer that failed to boot from a disk would display "No ROM BASIC" and halt (in response to interrupt 18h).

Later computers would display a message like "No bootable disk found"; some would prompt for a disk to be inserted and a key to be pressed to retry the boot process. A modern BIOS may display nothing or may automatically enter the BIOS configuration utility when the boot process fails.