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. Allison
