NorthStar Horizon

Posted by musovern on Aug 12th, 2024 in NorthStar Horizon, S100 | 0 comments

Introducing the NorthStar Horizon: A Pioneer in Personal Computing

The NorthStar Horizon, launched in 1977, is a standout in the early era of personal computing, notable for its unique blend of aesthetics and functionality. With its distinctive blue metal chassis and elegant wooden case top, the Horizon offered a stylish yet practical design that set it apart from other computers of its time. Powered by the versatile Zilog Z80 processor and featuring an expandable S-100 bus architecture, the Horizon catered to both hobbyists and professionals alike. It supported up to 64KB of RAM and was among the first systems to include an integrated floppy disk drive, which revolutionized data storage for small businesses and home users. Compatible with a wide range of software, including the CP/M operating system and NSDOS (North Star’s proprietary Disk Operating System), a standard North Star system sported one or two hard-sectored single sided 5.25 inch floppy disk drives, the NorthStar Horizon quickly became a favorite in the microcomputer community, representing a perfect marriage of form and function during the dawn of the personal computing era.

A few months back I picked up a couple of Northstar Horizon computers. That needed restoring.

System number one with the two shugart SA400 Floppy Drives.

System number two with the two Tandon TM-100 Floppy Drives.

And now on to the Restore I stripped down both units and gave them a good clean and checked over the motherboard for broken traces and bad IC’s

Started on the Capacitor reforming

Using a NICE” Z80 In-Circuit Emulator for test the RAM board

Z80 CPU board running at 4 mhz (ZPB-A)

32K Dynamic RAM board (RAM-32-A) modded for 64k system came with two of these.

MDS-A-D Double Density Floppy Disk Controller

Measurement Systems & Controls – DM6400 Dynamic RAM

My home brew 32k RAM board for testing before putting in the original RAM boards.

Thanks the Mike Douglas for his Vector Graphic Extended System Monitor 4.0c modified to run on a North Star Horizon computer system is now restored and booting CPM.