4 Jan
2014
4 Jan
'14
2:53 a.m.
Hi all,
I'm trying to use the AltairZ80 simulator to patch a Northstar .nsi disk image, with
the final goal being to use it with my real SOL-20 + Northstar disk controller. I will use
Dave Dunfield's NST utilities to copy over the patched Northstar .NSI image via serial
to my real SOL-20, and hopefully I will be able to generate a working CP/M 2.2 boot
floppy. I have Dave's NST utils already 'talking' to my SOL, so hopefully the
last part, generating a real floppy, should not be difficult.
I have the following files:
- A disassembled dump of the SOL-20 CP/M CBIOS (found on the net)
- A HEX file of the SOL-20 CBIOS that I generated in the AltairZ80 simulator
- A Northstar .nsi CP/M disk image that is bootable in AltairZ80 by 'Attaching'
MDSAD, Northstar MDS-AD Disk Controller (Memory Mapped to 0xE800-0xEBFF)
Now before I actually get into the nitty gritty of patching the SOL-20 CBIOS (which I will
also probably need some advice with) onto the Northstar disk image, I figured I need to
first find a way to copy the CBIOS HEX file that I generated, from the PC (or from the
standard CP/M disk image) onto the Northstar disk image. The standard CP/M disk image that
comes with AltairZ80 has two programs, 'R' and 'W' that allow copying to
and from the simulator to the PC. The Northstar disk image I have, of course, does not
have these two programs.
Now my first problem is to either get 'R' and 'W' onto the Northstar disk
image, and/or have the standard CP/M disk image mounted as drive A and the Northstar Disk
as drive B. I was hopeful that It would be easy to attach the standard CP/M image and the
Northstar CP/M image at the same time, and just copy the files over from one to the other.
However I can't seem to do this. I have tried various sequences of attaching the
standard CP/M disk image to drive A, then ?enabling? the Northstar controller and
attaching the Northstar disk image to drive B, then either trying to boot from A or B.
Unfortunately this does not work and CP/M does not boot, and results in some strange
activity in the simulator.
As many of you know, I'm a bit of a noob at this stuff, so hopefully I haven?t made
any wrong assumptions about what I need to achieve.
I was wondering if anyone had any idea how I can go about this?
Much thanks in advance.
Philip