Archiving Software - test-drb@ccmp.vtda.org

16 Dec 2005

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Subject: Re: Archiving Software
   From: Jules Richardson <julesrichardsonuk at yahoo.co.uk>
   Date: Fri, 16 Dec 2005 12:01:51 +0000
     To: General Discussion: On-Topic and Off-Topic Posts <cctalk at
classiccmp.org>

M H Stein wrote:
  Aside from bootable system disks, for which Dave
Dunfield's imaging program
 seems to be a much better solution than Teledisk, what's the best way to 
 archive software in a way that makes it as universally useable as possible and 
 downloadable/emailable? 
ImageDisk seems like a definite step in the right direction - it's certainly 
done a brilliant job when I've tried it.

What it now needs IMHO is multi-platform support so that you don't *have* to 
use DOS and so that it can be used by more people. (Whether a Windows version 
is viable I don't know; certainly Linux seems to give you all sorts of ways to 
reach the bare hardware though - presumably *BSD would be the same)

Other than that it seems a viable tool to use - the file format has a comment 
field of unlimited length for any useful metadata, and is able to record where 
bad spots were on the original disk. 
My solution for CP/M disk so I can work at the file level is to use one of 
David's emulators and serial down/up load the content using xmodem to either
a copy of Procom running on the same box or to a real CP/M crate.  The SIM
to Procom thing has caveats (I had to fire up a win98se box) as NT is to fussy 
about touching the metal.  However, once i had the w98se engine going I had to
loop com1 to com2 (real wire!) worked well using the Horizon Sim.  The first
case was Sim to real CP/M machine and that neatly sidesteps the old two systems
common OS incompatable media.

...
   For example, I
have original distribution diskettes for CP/M Wordstar, 
 Supercalc, etc. on 8" disks. Obviously images wouldn't be very useful for 
 someone with only 5" drives or no 8" drive on the PC; on the other hand, 
 a DOS ZIP file of the files on that disk would have to be copied/converted 
 back to a CP/M format disk somehow.  
Well the ImageDisk file format's public - I suppose there's nothing to stop 
someone writing utilities to pull data out of an image at the file level, then 
spitting them across a serial link with a terminal app to the original 
hardware. Or converting them back into a 5.25" image file, say. 
If you want to get/put files on CP/M disks the problem is one level more 
complex.  To do image manipulation of CP/M disks the utility must understand
CP/M filesystem AND know the know the internal format of the media imaged.
For example the internal format of a single density NS* CP/M disk is layed
out different from a Compupro CP/M image internally.  Reason for that is CP/M
applies allocation blocks of differing granularity that is disk size dependent
and also sector skewing.  So to read or write the internal file you need to run
the equivilent of a CP/M BDOS and disk portion of the BIOS.  Not that difficult
but certainly more effort.  The ugly part is getting the CP/M disk parameter
table and sector skew data into the tool for each imaged cp/m disk.

...
 Getting the data off (and knowing you've captured
it all) and onto modern 
media is probably more important than what tools someone may use in the future 
to interpret the data. Providing it's all captured of course! 
Without a doubt.

...
   So, how are
the rest of you dealing with this? 
Burying heads in sand I suspect :) I've finally got a PC that'll handle FM 
data (I think it was the 7th one I tried!), so I can start imaging my own 
collection. Luckily I just have soft-sectored MFM/FM disks here; no 
hard-sectored stuff, GCR encoded media etc. 
For NS* hard sector a real NS* and the Sim work fine.  For others I have
real systems and serial ports.

...
 I need to make the host machine dual-boot DOS/Linux so
I can just use DOS to 
the actual reading/writing, then Linux for everything else (archival, any 
processing of the files, taking advantage of being able to use longer 
filenames etc.).

I'll give DOSEMU a try under Linux to see if it'll run ImageDisk, but I 
suspect it won't allow the necessary direct access to the hardware... but I'm 
happy to dedicate a box to disk imaging, so it doesn't really matter if the 
Linux floppy subsystem gets clobbered in the process. I suspect that ImageDisk 
won't even run under DOSEMU though. 
Dos is not as bothersome as full out winders. though I've found my W9x boxes
do this well enough and as demonstrated I can run sim to procom so sim to sim
may be possible on one box and with two boxes no question.

Allison