A modern, scratch-built, open-source (GPLv3) alternative ROM BIOS for PC, XT, 8088 Clone or Turbo PCs.

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(General Libraries and Basic Input Output System)

A modern, scratch-built, open-source alternative BIOS for vintage PC, XT, 8088 Clone or Turbo PCs.

Copyright © 2022-2024, 640KB and contributors.

Stable Version 0.2:

Download ROMs

Source Code


Platforms Supported

Companion ROMs

Companion ROMs are PC Option ROMs that add additional features and support to any standard BIOS (not just GLaBIOS).


Why another 8088 PC BIOS in 2022 2023 2024?

There are other excellent BIOS projects out there each with it’s own design goals and use cases. The goals for GLaBIOS are:

  1. A collborative learning effort among the Retro Community
  2. A fully open-source PC BIOS, built and improved by the community, free of outside proprietary or copyrighted code
  3. Feature-complete with full support for original vintage hardware as well as new projects

Where did the name originate?

If you aren’t familiar with the reference, ask a gamer.

How can I try it?

Click here for how to make the BIOS ROMs.

OR try it LIVE!

Building GLaBIOS

How to Build Wiki page

More questions?

Check out the Wiki!


VGA with 8087 FPU and GLaTICK:

ss_0 2 5_vga_fpu_1 png

EGA with V20:

Screenshot VGA 07-29-22

CGA with 736K memory:

Screenshot CGA 09-08-22

Bad RAM detected! Use standard address and bit indicator to locate failed IC:

Screenshot CGA 09-08-22

5150 with cassette:

Screenshot 5150 Cas1


1-2-3 ver 1A

Screenshot 123 08-01-22

Flight Simulator 1.0

Screenshot FS1 08-01-22


Please send bug reports, feedback, questions or thoughts to or submit an Issue.

References and Credits:

Further Credits to:



This project is built upon the collective knowledge of the community by and for the benefit of the community. Unless stated otherwise, cited public sources are considered as “public domain” or “fair use” of the copyrighted material as provided for in section 107 of the US Copyright Law. If your copyrighted material appears in this project or on this web site and you disagree with our assessment that it constitutes “fair use,” contact us.