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The Northstar Horizon Computer

Manufacturer NorthStar
Model Horizon
Date Announced 1977
Date Canceled Early 1980s
Number Produced Tens to hundreds of thousands
Country of Origin USA
Price $2,400 assembled with two drives
Current Value $50-$250
Processor Zilog Z-80
Speed 4 MHz
RAM 16-64K
ROM Unknown
Storage One or two built-in 5.25 floppy drives (90k to 360k), later models had optional hard drives.
Expansion 12 slots
Bus S-100
Video Terminal or optional S-100 video cards
I/O Parallel, Serial
OS Options CP/M, NorthStar DOS
Notes Northstar started out by selling very popular 5.25" disk subsystems for a variety of S-100 machines. They eventually put together a box of their own.
Related Items in Collection Original manuals, software including WordStar, CP/M, NorthStar DOS and more.
Related Items Wanted Additional software.

There are currently two NorthStar Horizons in my collection and both are very complete with all of the original documentation, software and more. Both machines have the wooden covers which made these machines very distinctive in their day.

One machine contains a variety of cards including an old video card while the other is more standard and intended for use with a dumb terminal. Both machines work flawlessly.

Additional photos will follow as time permits.

(Submitted December 13, 2011 19:21:28 by Don Burbach)

I had a NorthStar Horizon with 56K memory, Z-80, and two Morrow ThinkerToy 8 600K floppys, and a Televideo 910 Monitor.

I acquired the machine from a friend who envied my Apple II w/Z-80 CPM softcard. He had the NorthStar and didn't have any user applications for it, but there were many commercial apps for the Apple II. We met at a Long Island Computer Association meeting in the early 80's. became friends, and eventually traded computers. We've remained in touch since, but I moved to CA in 1989 to work in Silicon Valley.

My hobbyist computers today are Quad PCs with terrabyte disks. A long way from the 8 floppy 600Kb disks which were cool because I had an almost infinite supplied of use disks.

(Submitted January 19, 2010 08:35:40 by Rod Smallwood)

Having written software on a Northstar Horizion years ago. I'm trying to get one together. I already have a motherboard. There's one small problem. I'm in the UK so shipping heavy parts is a big issue.

(Submitted December 30, 2009 08:01:57 by John)

Greetings - The Horizon was my very first computer and was built from a kit. I recently obtained an old Horizon to restore and will eventually need to deal with obtaining software and hard sectored disks. Any pointers would be appreciated.

john - colorado springs, co

(Submitted October 12, 2009 18:57:15 by Leonard)

My horizon had a 5 meg h.d- endless storage in those days. I swapped the system to someone; what a fool I was!

(Submitted January 20, 2009 20:42:12 by Bill Grote)

I have a Northstar Horizon and another Northstar computer I would like to sell. Also have one metal monitor and metal keyboard. These are all really heavy computer parts. But I'm willing to part with them if someone would like to buy them.

(Submitted August 28, 2007 05:23:23 by F.Baube)

North Star was notable for producing a multi-user machine. Of course, it was multi-user in the sense that each user had their own copy of the O/S; it was not multi-user in the UNIX sense.

(Submitted June 4, 2007 08:19:56 by Andrew Lynch)

I bought an old NorthStar Horizon a few weeks ago and have been restoring it since. It is a wonderful machine and there is a good amount of information on the internet to support it.

Although initially the machine was very broken and after some extensive repairs it is working well. I am transferring the original floppy disks to CD-ROM readable by modern computers.

If you have your data trapped on an old NorthStar Horizon hard sector floppy disks you would like recovered contact me and maybe we can work something out. If the email does not work, try the S-100 forum or PM me on this site.


Andrew Lynch

(Submitted May 26, 2007 00:30:40 by Dave)

I am in s. Florida, used to work for a Northstar dealer. His father passed away so he had to quit the computer business and run his father's business. I inherited a lot of his Northstar stuff. 1 Horizon, 2 Advantages, and more software than any one person needs. I don't need any of it. How close to S. Florida are You?

(Submitted April 11, 2007 10:53:53 by Andy Wing)

I remember using DASoft on one of these for circuit design on an HP plotter. We also had to patch some routines in CP/M to handle a third party quad density drive.

(Submitted March 15, 2007 08:33:01 by Tim Deaton)

I became a dealer in 1977 or so and still serviced equipment until I retired in 1997. I have a LARGE stash of Horizons, Advantages, and a couple of Dimensions as well as software, parts and terminals. They need a good home. Tim Deaton 317-716-8807

(Submitted November 19, 2006 09:39:37 by Dick Archer)

I was also a reseller (late '70s & early 80's) specializing in Wordstar-based systems for law firms. Back then, a complete system with dual floppies, all software and a daisy-wheel printer went for about $10,000!

(Submitted October 29, 2006 21:39:59 by Jim Dobson)

I enjoyed your site.

(Submitted September 19, 2006 00:38:31 by Paul)

Mine still runs today too. I rewrote the CP/M OS to handle more memory, faster disk I/O and multitasking back then. It has a user interface with mouse (trackball in those days) It has 512 kb Ram and 512 Kb Eprom. It all works with memory bank switching. All software is burned into Eproms, so it doesn't need the drives to run. Learned a lot with this machine. I still love it

(Submitted August 21, 2006 21:34:15 by David Slater)

I was a reseller of these machines in the UK. There was a multiuser version of the basic that would support up to 4 users meant really for college use. A colleague wrote an Estate Agent (Realtor) property matching system we implemented with 4 RS232 Terminals to one of these. Then at end of day we would reboot into standard CP/M and printout mailings with Wordstar / Mailmerge. Amazing ability on such a simple old machine. Anyone here remember Comart and the Byteshops?

(Submitted July 31, 2006 19:14:51 by Jonathan King)

Great machine. Mine still runs today!

Facts about the Horizon:

RAM: 16K to 63K Static RAM (16K per S-100 board)

ROM: 1K Bootstrap ROM (E800 to EBFF) pesky location

PORTS: 1-2 Parallel and 1-2 Serial. The serial ports where configurable via dip-header (110 to 9600 baud)

CLOCK: Not really. There was a Real Time Clock on motherboard with configurable intervals from 3.32ms to 27.26s that you could create a software clock from, however the clock lost time during disk interaction.

CPU: I believe early systems had the Intel 8080

Included Software (all Intel 8080 code): NorthStar DOS (3,328 bytes) Northstar Basic (~16KB) Northstar Monitor: Memory Editor

(Submitted July 23, 2006 08:54:51 by malac)

Just to know if u still have 't for sale. i wll like u to send the full picx to me. and i wll also want to know the last price r u going to sale 't. and were is 't now. i am interested in buying it , i wll like to hear from you as soon as possible. ,



(Submitted June 29, 2006 02:39:02 by Peter Jones)

Your site is very useful.

(Submitted September 12, 2005 18:42:41 by Michael Edelman)

The Horizon was my first computer. I bought it with 32K (two 16K boards), 6 S-100 connectors and a single serial port, and later installed more connectors and a second port. I ran the Northstar OS, CP/M, and later, a FORTH system that I ran my first MA research program on. I even used it to write my MA thesis using Wordstar. I think my father and I paid $2,000 or $3,000 for it, plus $1,000 for a Micro-Term Mime 2A terminal. That's more than the new car I bought at the time cost! We later added an Epson 80MX printer for around $500.

(Submitted January 10, 2005 08:22:09 by Stuart Bell)

OS options also included the UCSD p-System with a full Pascal development system that ran very nicely in 56Kb. I taught Pascal on Horizons in the early 1980s.

(Submitted December 23, 2004 06:28:40 by Burnsie)

I cut my computing teeth on this machine at colledge. We had 12 networked North Stars and had great fun learning on them. A few of us even wrote a CP/M virus back in 1980 (nothing distructive, just putting a ghost on the screen). Shortly after I left the college moved onto the North Star Advantage with a build in screen before moving to IMB PCs a few years later.

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