North Star Computers

Disk controller and drive

North Star Single Density Disk Controller, Shugart SA-400 Disk Drive and Floating Board Board

In the early days of 8080 eight-bit computers, users bought either an Altair or IMSAI S-100 bus computers. To make them operational, the user toggled in a bootstrap loader from the front panel that allowed would read a BASIC interpreter from either an optical paper tape reader or a cassette tape. After the BASIC interpreter was loaded, the user could key in a program.

In 1978 the North Star disk system came to market with was a 5 inch Shugart disk drive that held 89 kilobytes of storage coupled to an S-100 buss controller, cable with North Star DOS and BASIC.  It cost $700.00 in kit form and was the first floppy disk system that was affordable to hobbyists.

The front panel of the computer could be addressed to E800 hex, hit the load then run switch, and within a few seconds the North Star DOS prompt would display, (providing you could understand how to configure your computer system for your terminal or video display card.)  Once you had the DOS prompt, you could run the BASIC interpreter, load a program, save a file and make file calls from the BASIC. It was absolutely Great!

North Star Computers was the brainchild of Drs. Chuck Grant and Mark Greenberg. Their next product was the North Star Horizon which was an S-100 buss computer with two floppy disk drives, (which soon became double density, then double sided) which gave them a capacity of 360 Kbytes per disk drive. Later an 18 megabyte Winchester drive could be added to the parallel port. Though it competed with other computers and the 8 inch disk format, the North Star Horizon was a very popular computer in the era from 1979 to 1985.


After the Horizon came the Advantage and the Dimension.

A few of us were lucky enough to be a part of North Star during that time.

North Star Brochure May 1980

1 thought on “North Star Computers”

  1. Hi Alan: I thought the kit was $700 for employees, not for everyone? As one of your employees, that’s what I paid. But I have a real question: I had hoped to find the circuit diagram for a Horizon memory board, as I suspect the addressing models what is done today. Probably impossible to find, and it may also be impossible for me to understand it, as I am no long 29 years old. I did learn that DRAM still has a refresh rate of 60 ms intervals, leading me to believe row-select followed by column-select has also been conserved.

    Hope you get this message. I am still around, having survived some heart issues three years ago, despite exercising, eating well, and so on. Stress, however, was still on the menu.

    And I am still working…


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