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Super PC/Turbo XT BIOS 3.0

AuthorPlasma (Jon Ρetrosky and Ya'akov Miles)
ReleasedNov 8 2016
LanguageAssembly (IDEAL)

The Super PC/Turbo XT BIOS is heavily modified version of the widely-distributed "(c) Anonymous Generic Turbo XT" BIOS. It is a drop-in replacement for the IBM 5150/5155/5160 BIOS and most XT clones, including 8/10 MHz turbo systems.

Besides fixing several bugs from the Generic BIOS, many additional features have been added, including CPU/FPU detection, fast memory checking, UMB initialization, expansion ROMs in the F000-FE00 region, ROM BASIC boot option, 101-key enhanced keyboard support, and more.

All the tools required to modify and build the BIOS in are included, in DOS, Windows, or Linux.

Version 3.0 Changes:


  • TASM replaced with Open Watcom Assembler (WASM)
  • Win32 and Linux versions of tools now included so BIOS can be built in more environments
  • Disassembly listing now automatically generated


  • Ably-Tech HD Floppy BIOS replaced with Sergey's Floppy BIOS 2.2
  • Western Digital IDE SuperBIOS replaced with XT-IDE Universal BIOS r591
  • Future Domain TMC-850M BIOS removed
  • Option added to batch files to exclude IBM ROM BASIC


  • First pass at optimizing code for space
  • Some instructions corrected for stricter assemblers
  • Slight modifications to assemble with WASM (still assembles with TASM)
  • Location of strings and procs optimized to maximize continguous free space for additional code
  • Free space now filled with 90h instead of FFh so it appears more unique in a hex editor


  • ROM_START and ROM_END defines set scanning region for expansion ROMs (can overlap BASIC region)
  • Option to delay after expansion ROMs init before clearing screen (ROM_DELAY)
  • Option to always retry disk boot, even if ROM BASIC present (define RETRY_DISK)
  • Keyboard buffer cleared after memory check so BASIC prompt isn't accidentally skipped
  • Added base port 2C0h to RTC (clock) detection
  • Option for title bar "fade"


  • Memory check now 16-bit access; will be faster on 8086/V30 and some emulators



Click the filename to download the file.

Name Size Filename
Super PC/Turbo XT BIOS 3.0 1.9 mb
Super PC/Turbo XT BIOS 2.6 650 kb
Super PC/Turbo XT BIOS 2.5 641 kb
Super PC/Turbo XT BIOS 2.4 640 kb
Super PC/Turbo XT BIOS 2.3 639 kb
Super PC/Turbo XT BIOS 2.2 645 kb
Super PC/Turbo XT BIOS 2.1 612 kb
Turbo XT BIOS 2.0 646 kb


Click to see the full image.

Boot screen with 8088 and MDA
Boot screen with V20 and CGA
Boot screen with V20 and VGA