here are some ways to enter the bios, not sure if all of them are accurate:
METHOD--------------------------------------------------SYSTEM
Del during boot-----------------------------------------AMI, Award
Esc during boot----------------------------------------Toshiba
F1 during boot------------------------------------------Toshiba; Phoenix; Late model PS/1 Value Point and 330s
F2 during boot------------------------------------------NEC
F10 when square in top RH corner of screen--------------Compaq
Ins during boot-----------------------------------------IBM PS/2s w/ Reference Partition
Reset twice---------------------------------------------Some Dells
Alt Enter-------------------------------------------------Dell
Alt ?-------------------------------------------------------Some PS/2s
Ctrl-Esc--------------------------------------------------General
Ctrl Ins---------------------------------------------------Some PS/2s when pointer at top right of screen
Ctrl Alt Esc--------------------------------------------AST Advantage, Award, Tandon
Ctrl Alt +------------------------------------------------General
Ctrl Alt S------------------------------------------------Phoenix
Ctrl Alt Ins----------------------------------------------Zenith, Phoenix
Ctrl S-----------------------------------------------------Phoenix
Ctrl Shift Esc------------------------------------------Tandon 386
Shift Ctrl Alt + Num Pad Del--------------------Olivetti PC Pro
Setup disk---------------------------------------------Old Compaqs, Epson (Gemini), IBM, IBM PS/2, Toshiba, most old 286s