What I would do personally is:
1. Run in an emulator such as the ones linked above, it will be heaps easier than the bare hardware. Need not emulate your particular machine. Preferably would emulate your Z800x CPU but even that isn't 100% essential.
2. Get yourself a 2.11bsd filesystem, best way might be install or download 2.11bsd for PDP-11 and run in simh. Hopefully the simulated disk is in raw form so it can be moved between simh and your emulator, otherwise you could modify one of the emulators or convert the file somehow.
3. Figure out a way of copying between your real disk and your simulated disk. For example run an sshd under simh and "scp" to your disk. Or mount your file as a tape and "dd" it over to your disk with correct name. Or whatever, there could be existing utilities that can do this. (Kind of like msdosutils on linux has a userspace implementation of vfat and can do simple things to vfat formatted floppies or disk images).
4. Figure out how the bootstrap works and translate it to Z800x assembly. In essence the boot sector will load the next 16 or so sectors into memory and jump to it. Those 16 sectors contain a cutdown version of a 2.11bsd filesystem mounted rdonly, enough to read superblock, locate inode table, maybe locate /boot/kernel and then load and jump to it. I can send some examples in Z80 code for my project. Or I can take a look in 2.11bsd and tell you how this works.
5. You now have a cross assembler and linker and a development system. Get C working too. Compile the kernel with as many things as possible disabled -- no disk, network, etc. Find a way for dprintf() or similar to work -- such as polled output to a serial port, or even just defining an unused Z8001 opcode to putchar() whatever is in R1. No need for any finesse here.
6. In the first line of the kernel startup put a dprintf of "hello world". Copy resulting kernel to /boot/kernel or whatever it is supposed to be called. Put similar diagnostics in your bootstrap. Run and debug until your messages come out. Then gradually step through the kernel initialization and main loop fixing things as you go. Eventually add more subsystems.
Nick
Oliver Lehmann wrote:
William Pechter <pechter@gmail.com> wrote:
I found this for a Z8000 System III box. It was an East German dual cpu Z80/Z8001 clone box running SysIII -- perhaps this may be of some help as a comparison.
And I also redid (disassembled objects, translated it back to C) nearly
all Kernel sources of the SYSIII (only lock.c is missing with file
locking features - I only disassembled it)
https://github.com/OlliL/P8000/tree/master/WEGA/src/uts
Emulator
http://www.knothusa.net/Home.php
Yes... he built the Emulator based on MAME back in 2008 with quite
some info from me - he used to work on a P8000 back in the 90s so
he felt for it building the Emulator.... ;)
More P8000 info
http://www.pofo.de/P8000/
Z8000 docs
http://www.pofo.de/P8000/ (there's some Zilog System 8000 Z8000 Zeus info here as well.
Cool... you found my page ;)
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Nice site... I worked for DEC back in the 80's and I ended up installing Exxon Office Systems' Vaxes which
they used for software development for the Zeus systems. Some employees were from the Berkeley area
and New Jersey, even Princeton, seemed to be culture shock.
The computer room was directly under the flight path to the little Princeton Airport and the rented building
wasn't really designed for those machines. The place was small offices for insurance sales, accounting,
lawyers and such. They later moved over to a new building on the RT 1 corridor which had a real computer room after they had all the electricity put in for the 11/780.
They moved from California to Princeton, New Jersey back around '81 or so and were gone shortly
when Exxon closed them down in '84.
I think they were the first Ultrix32 box I saw in my lifetime... which was much more AT&T focused working
for DEC in New Jersey. By 92 or so I was doing SunOS 4.1.3 at work and FreeBSD/NetBSD at home.
I never could figure out how AT&T kept the miserable self-destructive Unix Filesystem alive with it's 13 character filename limit and no symbolic links. SysVR4 finally showed some promise, and I even
thought they had a winner with their object-oriented management tools to manage getty's and printers and such.
FACE, the SVR4 character terminal graphic utilities were not too bad. You could finally run the whole system without vi-ing configurations -- kind of like a pre-SUSE Yast that used the button labels on function keys.
Perkin-Elmer/Concurrent had a similar thing in Xelos (SVR2) on their block-mode capable 1251 and 6312
terminals... That was the thing in the 80's -- menu or function button Unix sysadmin screens.
AT&T killed their future OEM's by allowing the OSF/USL split to happen over their Sun investment
and promise that Sun would get the new Unix before everyone else. The Unix wars made sure there
wouldn't be one binary/source compatible version of Unix across all hardware platforms.
When I started to work with Solaris2 I was amazed as to how different it seemed than straight SVR4 and
I helped write Pyramid's training for their OS/x SVR4 MIPS R3000 product.
Had AT&T been more willing to supply the code equally and get out of the way you wouldn't have had
the waste of the NCR purchase later after the less than stellar 3b and 3b2 sales of the late 80's.
To bring this back to the Z8000 ZEUS and Zilog:
Pyramid was an OEM for AT&T and AT&T was to sell Pyramid boxes to the US Government to replace
the Z8000 Zilog Zeus machines which were used by the IRS. I think this all fell apart after the
NCR purchase. My job kind of went with it as Pyramid went through a downward sales spiral
as AT&T stopped buying MIServers and the MIPS MIServer-S line (R3000 SVR4) multicpu boxes.
Bill
--
Digital had it then. Don't you wish you could buy it now!
pechter-at-gmail.com http://xkcd.com/705/
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