Extended BIOS may refer to:
XIOS, the extended BIOS in Digital Research's MP/M, Concurrent CP/M, Concurrent DOS, Multiuser DOS and REAL/32 (since 1979) XBIOS, the extended BIOS in Atari TOS-based computers (since 1984/1985)
EX-BIOS, non-standard BIOS extensions in the HP Vectra series of computers (since 1985)
See also BIOS extension Enhanced BIOS (LBA) VESA BIOS Extensions (VBE)