Watzman at neo.rr.com
Sat Nov 25 14:02:16 CST 2006
Re: "But you will have a bit of a "chicken and egg" problem - the NorthStar
disks are hard-sectored, which means that you can only make them on a system
with the NorthStar controller. Unless you have other N* systems kicking
around you will have to use the Horizon. But the Horizon has no front
panel, or other means to easily bootstrap code into it other than the disk
Install the North Star disk controller card into a CP/M system configured
such that there are no memory or I/O port conflicts. Then you can assemble
source code of the NorthStar DOS using CP/M's ASM, and load it into RAM
using DDT. There are routines in the NorthStar ROM (which will now exist in
the CP/M system) for formatting a disk and writing out RAM to the diskette.
It's possible for a NorthStar controller and a typical CP/M soft sector
controller to co-exist in the same system at the same time, if you resolve
any I/O port and memory conflicts. This allows the use of CP/M and all of
it's facilities (in particular, source code editors, ASM and DDT) to create
a first NorthStar diskette.
Date: Sat, 25 Nov 2006 06:56:50 -0500
From: "Dave Dunfield" <dave06a at dunfield.com>
Subject: Re: Northstar Horizon
To: "General Discussion: On-Topic and Off-Topic Posts"
<cctalk at classiccmp.org>
Message-ID: <200611251101.kAPB1t0K026282 at hosting.monisys.ca>
> It has no diskette drives. The MDS-A3 card has a blown tantalum capacitor
> (C6) and the motherboard has a blown tantalum capacitor (C1). The
> motherboard is a HRZ-MB-4.
Make sure you have the disk controller designation right - My single density
NorthStar controllers are called MDC-An and the double density ones are
called MDS-AD(n). You need to figure out if you have a single density or
double density controller in order to determine which boot disk you need.
If it's MDS, I think it should be double-density, but I expected the latter
to be "-AD3". I have photos of both controller types on my site the
between a single-density and a double-density is easy to see .
> I'm going to clean it up and replace the blown caps and run some checks on
> the power supply. I also have downloaded the relevant documentation to
> the processor and disk controller cards, and also the HRZ-MB
I have a lot of NorthStar material and documentation on my site - much of it
the Altair section (One of my Altairs has a NorthStar controller).
> Assuming all goes well I need to get my hands on some disk images to run
> this system. Does anyone know where I can get such images? Also, can I use
> old IBM PC full-height 360K disk drives in this machine?
I have many images for both single and double density Horizon systems on my
site - if It's SD, your choices are NorthStar DOS and my own DMF system. If
DD, the choices are NorthStar DOS, CP/M and UCSD Pascal.
But you will have a bit of a "chicken and egg" problem - the NorthStar disks
hard-sectored, which means that you can only make them on a system with
the NorthStar controller. Unless you have other N* systems kicking around
you will have to use the Horizon.
But the Horizon has no front panel, or other means to easily bootstrap code
into it other than the disk drive. If you happen to have an S-100 ROM card,
you could use it to bootstrap the Horizon. I've got a very simple monitor
you can use to bootstrap in the NorthStar tools archive.
Also - in case you are not aware, the 10 sector diskette are physically
than a typical soft-sector diskette (11 sector holes instead of one) - you
10-sector diskettes for the Horizon which can be difficult to find.
dave06a (at) Dave Dunfield
dunfield (dot) Firmware development services & tools: www.dunfield.com
com Collector of vintage computing equipment:
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