SigmaSoft and Systems

Location: Dallas, TX

Previous Location: Kingston, OK

Note: Permission has been recieved from Clay Montgomery to post these manauls.

H/Z89 Hardware

SigmaSoft Ad

Interactive Graphics Controller(IGC)

Superior Graphics and A Pseudo Disk for $495

For H8-19, H88, and H/Z89-90, 640 x 250 resolution, provides up to 640 x 500 in interlace mode, and advanced high-level graphics language interface, a RAM-based disk drive emulator, two graphics input device ports and two Centronics parallel printer ports. $495

Manual: IGC Manual

Article: Interactive Graphics Controller

Ad for Interactive Graphics Controller

Hard Disk Systems

From 10 MB up to 67 MB. Includes Z37 compatible floppy disk controller. Uses a single left-side slot. Up to 16 Data partitions from HDOS, CP/M, or Both. Cold boots HDOS and Heath CP/M (requires MTR-90).

Ad for Disk System

Manual: Disk System User's Manual

Article: Hard Disk System

Technical Overview: Hard Disk System

Universal Parallel I/O Board $95

Provides two full Centronics parallel interfaces. Up to 3 board can be installed in an H89, providing up to 6 parallel devices. Supports printers, joysticks, and track

Ad for Parallel interface board

SigmaSound Board (Less Joystick) $95.00

Manual: Sound Effects Board User's Manual

Joystick Controllers (Set of Two) $25.00

SD.DVD Device Driver $10

Arcade Games Package (Requires Joysticks)



Computer Aided Drafting System for the H/Z-89 with the IGC.

Manual: CAD-89 User's Manual


Founder: Clay D. Montgomery

Current Status: closed


Last Modified: Sunday, 25-Feb-2024 22:34:45 PST

Contact Details

Mark Garlanger

Email: heathkit [at] garlanger [dot] com

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




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.