View Full Version : IBM DOSv4 from720K to 360K Diskettes?

March 18th, 2005, 01:06 AM
Help on this one please Guys.Cheers

joe sixpack
March 18th, 2005, 10:26 AM
ok this is sure speculation but you might try editing setup.ini
it contains the list of what files are on what disk's

other then that i dont know of anyway to convert a 720->360
unless the 720 has less then 360k on it.

you might try fooling the setup program with a program called "fakedisk"
or by using ramdisk but i think the setup has to be ran from it's boot disk.

if all else fails install 4.0 on someother system and then use the disk
to make the sytem you really want to install it on boot able with SYS comand
then just transfer all of the other systems files to the one with the 360k
drive. make sure you get all the files some are hidden like io.sys
This works on dos because config.sys & autoexec.bat are the only things
special from one dos machine to another.

I hope this helps you i know the last trick works because i just upgraded
one of my 486's this way.

March 18th, 2005, 12:08 PM
The genesis disk is always the hardest.

The easiest way is to have a system with both types of drives installed. This would be a later AT or 386 system with both a 1.44 MB drive (for reading the 720K diskettes) and a 5.25 double density floppy for writing.

Boot the system with your target OS, which is DOS 4. Then use format /s on the 5.25 inch drive to make a bootable DOS 4 diskette. Then hand copy the utilities that you need to the 5.25.

I had to do this when I had get DOS 5 and DOS 6 onto a PCjr.