Sol-20 and Helios pleas

From: Jim Battle <frustum_at_pacbell.net>
Date: Tue Jun 12 23:11:30 2001

At 07:53 AM 6/12/01 -0400, Douglas Quebbeman wrote:
>...
>Say, the PTDOS discussion just jogged my memory... wasn't someone
>in PROTEUS going to modify it so that it would support soft-sectored
>disk systems like the NorthStar and such? Do you know if that ever
>happened?

Contrary to your earlier surmise, I actually have only one complete SOLUS
NEWS issue. I have a jumble of disorganized copies that I haven't been
able to sort out yet.

However, the one issue that I do have talks about this mod. At least, I
think it is what you are talking about. The Vol 1, Num 5 issue (aug/sep
78) has an article by Ron Parsons called "A Soft-sector Disk Controller for
the Helios". The Helios disk controller remains the same, but his system
also has a Tarbell disk controller. Through extensive hardware and
software mods, he can mux between the original PT hard-sectored disk
controller to drive the Helios system, or toggle some flop to instead use
the soft-sectored Tarbell disk controller. The article has some code
snippets and a (partial?) schematic of the mod.

If you want it I can scan it and send it along to you.

>If not, I'll have to put that on my to-do list. But there are a few
>years' worth of projects ahead of it (CDC 6000 series simulator,
>PL/1 compiler, Multics simulator, Multics source code rescue, etc).

I know that feeling. I've found that I'm enjoying working on my Sol
emulator more than using the real system, so it has changed the nature of
my collecting/collection. I learn so much more in writing an emulator
because you really do have to understand every last bit. There are parts
of the machine that I thought I knew, but when it came time to write code
that handled every possibility, that's when I really had to learn how
things worked (not that I'd actually duplicate all functionality, but at
least I'd know which corners I was trimming).

Emulation projects (certainly not all of them will get done before I burn out):

         1) Sol emulator (Solace) -- northstar disk emulation, Helios disk
emulation, PT-DOS

         2) Wang 2200 emulator (I'll die happy if I can get this
running). CPU/keyboard/display/tape system. Floppy disk and hard disk are
not likely to be emulated. I just want to recreate the machine that taught
me how to program.

         Then in the back of my head, I'm toying with the idea of
graduating from software emulation to hardware emulation. It would be fun
to put a Wang 2200 on a 3"x3" pc board using a Xilinx, an SRAM, and an
EPROM. Video out would be standard baseband B&W video; the keyboard would
be a standard PS/2 PC keyboard mapped to look like the wang keyboard, plus
emulation of the cassette drive via a removable flash ROM cards.

         3) HP-85/86/87 emulator (cool little CPU) -- I have most all the
resources I need, but it will depend on time and getting legal approval
from HP.

         4) TI CC-40/TI-74. Another neat little CPU. I've contacted TI
legal and they gave me preliminary "I don't see why not" email, but it is
pending on them checking to make sure they didn't sell the I.P. for it to
some third party. I was impressed that T.I. would go along with the
joke. Likely to just be a minimalist job with no support for I/O other
than LCD and keyboard.


I'm in the process of selling off a good portion of my computer collection
to raise money for shipping the Wang system. Besides, the machines I'm
selling have already been emulated or aren't that interesting as emulation
targets.

>But if my sanity and health survives, it'll get done!

Good luck!

>Regards,
>-doug q

-----
Jim Battle == frustum_at_pacbell.net
Received on Tue Jun 12 2001 - 23:11:30 BST