Ultimeth Software

Dean Gibson from Ultimeth Software granted permission to post the software and manuals:

"Permission granted! Sincerely, Dean Gibson"

Ultimeth Software provided drivers for several different hardware items:

  • HDOS Hard-sectored driver supporting double-sided, 80-track floppy drives
  • HDOS MMS Soft-sector controller
  • MTRHEX / MTROCT - replace ROMS for the Heath H89 (ROM image) - (MTRHEX Manual).
  • MTRHEX-4k / MTROCT-4k - replace ROMS for the Heath H89 (ROM image) - (manual wanted).

The company is still in existence, see what they are up to on the Ultimeth Systems website.




Software Status

Manual Status

Original Price


HDOS hard-sectored driver supporting double-sided/80-track floppy disk drives





HDOS driver supporting Magnolia Microsystems 77316 Soft-sectored controller.





Last Modified: Sunday, 25-Feb-2024 22:50:02 PST

Contact Details

Mark Garlanger

Email: heathkit [at] garlanger [dot] com

If you email me, PLEASE check your spam filter for any responses.

Website: www.garlanger.com



This site is dedicated to preserving the history of the original Heathkit computers. They were initially release in 1977 and included the 8-bit H-8 and 16-bit H-11 systems. The H89 was released in 1979.