10 Jan
2006
10 Jan
'06
3:04 a.m.
Now the bad news: I thought I could "cheat the
system" by running ImageDisk
on Windows 2000, as I have some WordPerfect 6.1 disks I needed to try
to image. Yes, Right there in program documentation it says it won't run
on any Winders OS that uses good ol' HAL - that's the Hardware Abstraction
Layer for y'all that run the "good" OS's. ;-) Well, I tried to run it
in a
Winders98 install under VirtualPC under Winders 2000. I was hoping that
VirtualPC would open up the HAL enough on floppy access to allow ImageDisk
to do it's job. Well, it still didn't work. It tried awfully hard, but the
HAL just confused the bejeebers out of it. (At times, ID thought it was
reading a Single Density disk!)
IMD needs:
- unrestricted access to the floppy disk controller hardware.
- Nobody else messing with the FDC hardware/interrupts while it is
active.
- to not be held-up while some other task decides to hog the CPU for
a little while (there are real-time critical aspects to the analysis phase)
Winders 2K fails on pretty much all of the above. I haven't tried VPC, but
I would expect that the low-level floppy control remains with the host OS
(winders) and it's virtualized just enough to read/wrote PC disks. I also
would not expect it to stabalie the real-time charactistics of the system.
The good news is that IMD is tiny and can run from DOS booted off a
diskette. There's a bit of a catch-22 in that you can't write the image
file to the floppy while you are doing weird things to the FDC to read
a foregn format disk, however the easy work-around for that is to use
a RAMdisk.
So what you do is make up a DOS boot disk which defines a RAMdisk
and unpacks a few necessary commands onto it (including IMD), then
you can boot it and read disk images(s). At the end of the session,
you format a blank floppy and ZIP the images onto it from the RAMdisk.
Then you can boot winblows and slurp the files off the floppy.
If you have a network card that you can get 16-bit drivers for, you can
put a client on the boot disk and IMD the images directly into a network
directory.
If there's interest, I can put together a boot disk image which does this.
Another option if you have any unpartitioned space on your HD is to
just put on a small DOS partition. Either use a boot manager to boot
it directly, or boot a floppy and switch to it - either way, you can pull
the files off to winders later.
I guess I'll have to dig my old smellyron (er,
celeron) 533 system out of
mothballs which runs 98 & install/run it on there. It's just that I'm a bit
space-limited right now, and convincing the wife that I need room for a
permanent CoCo setup *and* yet another IBM are slim (and at this rate,
there's *no* chance for a little space for the Amiga 4000T in the near
future... :-/ ).
Btw - you can reduce the space requirements a lot by using a KVM
switch . (I put one on my test-bench last year and eliminated two
monitors/keyboards - very handy).
Dave
--
dave04a (at) Dave Dunfield
dunfield (dot) Firmware development services & tools: www.dunfield.com
com Collector of vintage computing equipment:
http://www.parse.com/~ddunfield/museum/index.html