North Star Computers

North Star's first product was the Floating Point Board, an S-100 bus card that implemented a floating point coprocessor for 8080-based machines.[4] The company later added RAM boards and Z80A processor cards to their lineup.[5]

North Star's next product was a hard sectored floppy disk system based on a 5-inch Shugart Associates SA-400 mechanism with 89 kB capacity. This was coupled with a S-100 bus controller and ROM that included bootstrap code and shipped with North Star DOS and North Star BASIC. The MDS system cost $699 and could be plugged into any S-100 bus machine, and was one of the earliest disk systems affordable for the average hobbyist. With the North Star installed, startup went from a lengthy process of manually entering a "loader" program through front-panel switches, to simply setting the run address to E800 on the address switches and flicking the RUN switch.[6]

North Star later updated the disk drive to support double-density disks with 180 kB, and later still double-sided, double-density disks with 360 kB of storage. However, the double-density product was pre-announced and sales of the original single-density, single-sided model ended overnight. The sudden loss of income almost bankrupted the company, and is used as an example of the Osborne effect in action.[7]

The Horizon was an 8-bit ZiLOG Z80A-based computer, typically with 16K to 64K of RAM. It had one or two single-sided single or double density hard sectored floppy disk drives (externally expandable to 3 or 4), and serial interfaces connected it to a computer terminal and a printer. It ran CP/M or North Star's own proprietary NSDOS. It also included many chips on the motherboard that would otherwise require separate S-100 cards in other systems, thereby allowing the machine to operate "out of the box" with minimal setup.

Announced in November 1977, the Horizon was one of the earliest systems to include built-in drives. The cabinet held up to 12 additional S-100 cards, with at least some of these used for memory cards. With one floppy drive the kit cost $1599, while an assembled system cost $1899. With two drives the kit cost $1999, while an assembled system cost $2349.[4]

Early machines used a wooden cabinet and sported a logo placard with the company name stylized "NorthStar". Later machines used an all-metal case and the name was separated (as in the image on this page).

The Advantage was a 4 MHz Z80a-based computer with 64 KB of user RAM and 16 KB of graphics RAM. It used two single-sided, double-density 180 KB floppy disk (hard-sectored) drives and an optional 5 MB Winchester disk. The Advantage was known for its 640×240 graphics capabilities and was sold with four demonstration programs, one of which plotted and calculated a pattern of lines reminiscent of the Arcade game Qix. The Advantage also had an optional 8088 co-processor board available that ran MS-DOS 1.0. When the Advantage was introduced NorthStar had moved its offices, manufacturing and warehousing facilities to 14440 Catalina St. in San Leandro, California. NorthStar remained at that location until they ceased operations.

The Dimension was a server computer, and North Star's first fully PC-compatible product. Based on the 80186 chip at the server, the Dimension employed multiple screens each connected to a PC-compatible 8086-based slot card that mounted in the server. The screens and keyboards then connected to the workstation cards in the server.[8] The unit shipped with MS-DOS and Novell NetWare was available as an option. The Dimension was North Star's last product, and did not enjoy the success of North Star's previous models.