Looking for North star software

allison allisonportable at gmail.com
Tue Jul 3 08:05:23 CDT 2018

On 07/02/2018 11:31 PM, Fred Cisin via cctalk wrote:
>>> BUT, the Horizon can also manage 8" drives (SSSD soft-sector CP/M
>>> standard!) with appropriate controller, or use other S100 FDC boards.
> On Mon, 2 Jul 2018, allison via cctalk wrote:
>> Really? not any of the MDS (SD or DD) controllers as they only know hard
>> sector.    A Soft sector controller with rom
>> on board then the situation changes.  Plan B is  a CPU with local eprom
>> and use that as the system monitor to boot
>> stuff to disk.
>> The standard NS controllers have only a small rom enough to boot a NS SD
>> or DD floppy using their controller
>> where the roms are.
>> . . . �   The older
>> of mine runs a MDC4 765 based soft sector
>> controller and is an active highly modded CPM system.  The other is
>> vanilla and tucked away.
> Really, I just assumed that you could install a non-NorthStar disk
> controller, in addition to the stock one, or maybe instead, in order
> to be able to do soft-sector.
You can but none of the NS* software will recognize it and it
effectively makes the Horizon just another nice S100 crate.
The NS* software is well wrapped around the hard sector controller which
is actually crude but effective.
Unplug the disk controller and the system has no rom or front panel. 

Its why I have two.  One is a basic 56K NS horizon where the only board
not NS* is the static 64K ram card.
The other is NS* horizon box and mother board aka the bus has all the IO
for serial, parallel and
hearbeat interrupt at one end. But a faster Z80 card (10MHZ modded
compupro) 256K of ram,
hard disk controller, soft sector controller (765based) and several
slave controllers for moving
stuff and printer buffering.   

A lot of the NS systems were improved with soft sector controllers and a
phantom rom card if the
controller didn't have one.  The box was good quality fair cooling and a
beefy power supply.


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