ImageDisk under Win2k (was: Thanks again, Dave!)

[Dave Dunfield]

> 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