Diskcopy for different formats

[jeeza]

Normally you can only copy a whole 3.5" diskette onto another one, or a 5.25" diskette onto another one, but on http://home7.inet.tele.dk/batfiles/msdos7/ (click on "Diskcopy" in the table)
they give a way of bypassing the normal workability of the Diskcopy DOS command.


Yes, you CAN diskcopy a 1.2M onto a 1.44M floppy -- BUT you need to be tricky. The easiest way to do it, is to use DEBUG or a disk editor and copy the boot sector of the 1.2M onto the boot sector of the 1.44M.

Then remove the 1.44M and access the 3.5" drive, abort at the error message. This forces DOS to recognize the floppy ain't there no more. When you re-insert the 1.44M with the 1.2M boot sector, DOS will read the boot sector and "recognize" the disk as a 1.2M formatted disk. NOW you can diskcopy from the 1.2M 5.25" floppy onto the "1.2M" 3.5" floppy.

This trick is useful when migrating old software's install disks to a machine with only a 3.5" drive. I have used it with several versions of DOS on several machines -- I only saw it fail once, on a machine with a strange BIOS that had lots of other compatibility problems.
But isn't there a contradiction in this ?
If you have a machine with only a 3.5" drive, how are you then going to copy the boot sector of the first diskette, if it's a 5.25" one, onto the 3.5" diskette ?

[pave_spectre]

It would require the presence of both a 3.5" (A: ) drive and a 5.25" (B: ) drive.

Then the new disks could be used on a machine with only a 3.5" drive.

[jeeza]

Hello there from down under.
That's what I thought. This trick isn't workable if you haven't already got a 5.25" drive.

[Paul Komski]

Drive Image comes with a handy app called "VF Editor", which allows you to create/compile/decompile the whole range of floppy formats and either save the result as a floppy image file or write it to the correct floppy diskette - and that includes those weird formats that the Win95 installation diskettes came in - for example.

I daresay there are other Virtual Floppy editors - but I have no experience of any others.

[jeeza]

So this app would copy any format to any other format ? Do I get it right ?

[Paul Komski]

Yes - within obvious limitations. As an example, a 3 1/2" HD floppy can be formatted out to 1.72 MB and a 5 1/4" HD can be formatted out to 1.44 MB. A larger image cannot be formatted into a smaller image.

However the files inside any image can be extracted and then injected back into two or more smaller formats.

[jeeza]

Originally posted by Paul Komski
Yes - within obvious limitations. As an example, a 3 1/2" HD floppy can be formatted out to 1.72 MB and a 5 1/4" HD can be formatted out to 1.44 MB. A larger image cannot be formatted into a smaller image.
What kind of media has a capacity of 1.72 MB ? Is this DD as opposed to HD floppy ?

[Paul Komski]

There are the standard formats of: 160KB, 180KB, 320KB, 360KB, 720KB, 1.2MB, 1.4MB as well as non-standard formats of 820KB, 1.72MB and the DMF formats of 1.68MB with their three different cluster sizes of 512, 1024 and 2048.

DMF Format (http://www.winimage.com/wimushlp/wini1a1y.htm)

I have Windows 95 installation diskettes, which are on DMF format and these are backed-up now as image files having used "VF image" to create them and since it is hard to come by blank 1.68 diskettes on which to make such backups. I am missing just 1 of the 13 diskettes however but hope to come by a replacement sooner or later.

Another utility (http://www.softcities.com/Alkonost-MaxFormat/transfer/3693.htm) that does something similar.