The Northstar disk system was quite an item in its day, when it came out it was the lowest price floppy disk system on the market, by about half (it was under $500, and most other SINGLE drive systems were $1,000). That's because it was the FIRST commercially available system to use a 5.25" drive rather than an 8" drive. The drive was the Shugart SA-400, I believe (could have the number wrong), a full-size 5.25" drive. As used by Northstar, it was a 35 track drive with ten sectors per track (hard sectored), 256 bytes per sector, I think, total capacity as formatted was 80k or so (with some reserved area) (single sided, single density, of course).
The controller was dumb, mostly just gates controlled by software. To step the drive, the software wrote alternating, and properly timed, "1's" and "0's" to a port or an address (my recollection is that the controller was memory mapped). All of the work was done at a very low level in the operating system, which was also dumb, it only supported contiguous files and you had to "compact" the disk whenever holes were created by deleting a file.
Many of us made our first move from paper or (audio) magnetic tape to disk with this system, and crude as the system was, it was a HUGE advance at the time.
And a small New York city software firm, Lifeboat associates, became quite prominent in part because they managed to put CP/M on the Northstar system, a major feat at the time as CP/M had been pretty much exclusively set up for standard 8" SSSD drives (in fact, in versions 1.3 and to a lesser extent 1.4, it was hard coded this way in the BDOS, but in version 2.2 it became table driven so that other formats were more easily accommodated). The two principles in Lifeboat I knew quite well, Tony Gold, who was mostly a promoter, sales type and businessman, and I can't remember the name of the primary programmer who did most of the actual software development work, but at the time I knew him quite well and worked closely with him on porting CP/M to the Heathkit products. I will remember his name shortly after I "send" this message.
I still have source code (disassembled and commented) for the Northstar Disk operating system.
Barry Watzman
----------
From: Jeffrey l Kaneko [SMTP:jeff.kaneko_at_juno.com]
Sent: Wednesday, December 09, 1998 9:53 AM
To: Discussion re-collecting of classic computers
Subject: Re: FSOT: Commodore GPIB cable.
Joe:
Okay, I have something that may interest you. One of Northstar's
first products, was a floppy disk drive, that could be used with
Altairs (among others). I have a pair of these 5.25" drives in an
aluminum/wooden cabinet.
There are inscriptions inside giving dates that it was built up,
upgraded, etc. I don't remember the exact dates, but it seems that
it was built in 1977.
I have reason to believe the drives are original; one still has the
N* nameplate attached thereto. The wooden top cover is in decent
shape, has a small bit of wood chipped from a front corner.
If this is interesting, I can get more particulars-- especially
corrolation of the dates with the actual Altair/Imsai/N* product
release timelines.
Jeff
On Wed, 09 Dec 1998 08:45:24 Joe <rigdonj_at_intellistar.net> writes:
>Jeff,
>
> That one is sold but I have another one that's still new in the bag.
> I'm
>looking for anything for my Altair, anything for my Tektronix 4051 or
>HP
>calculator or computer stuff. Machines, parts, manuals or whatever.
>
> Joe
>
>At 08:31 PM 12/8/98 -0600, you wrote:
>>Joe:
>>
>>I could sure use this. WHat sort of trades are you looking for?
>>
>>Jeff
>>
>>On Tue, 08 Dec 1998 14:17:39 Joe <rigdonj_at_intellistar.net> writes:
>>>Commodore marked cable with a card edge connector on one end and a
>>>male/female GPIB connectors on the other. Contact me if interested.
>>>
>>> Joe
>>>
>>>
>>
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>
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Received on Wed Dec 09 1998 - 19:02:15 GMT