This page covers only the proprietary BIOS developed by Compaq. Other types of BIOSes used by Compaq computers are not covered in this page.
Compaq was one of the earliest developers of BIOS, creating the first instance of its own BIOS firmware in 1983 for the Compaq Portable PC. This was less than a year before the release of PhoenixBIOS, the first commercially available BIOS firmware developed by Phoenix Technologies. Despite this, alongside the availability of other commercial solutions such as AMIBIOS from American Megatrends (now AMI Inc.) and AwardBIOS from Award Software, Compaq continued to develop its own BIOS for many years until it was acquired by Hewlett-Packard (HP) in 2002. After the acquisition, HP continued to develop and use this BIOS for a few more years (specifically for the HP-Compaq line of computers), until it was discontinued in favor of commercial BIOS solutions and, shortly thereafter, UEFI-based solutions (mostly AMI Aptio).
Below is a list of significant changes made to this BIOS during its development. As Compaq never used version numbers to identify their BIOS core versions (they were only used for ROM releases for each computer model), these changes are listed by the approximate year they first appeared in known/tested ROMs. Therefore, inaccuracies may be present in the information contained in this list.