I already posted this in another thread, but since there's a few people have had this problem, I thought it'd be useful to post a new thread.
Those of you trying to install the floppy disk version of OS/2 Warp 3 on Virtual PC, and having trouble with the XDF format used on disk 2 onwards, here's how I made it work on VPC 2004 SP1 (may or may not work on earlier versions - not tested!) :
1. Make images of all of your OS/2 Warp disks. The Installation Disk and Disk 1 can be handled in the normal way (WinImage, "dd" under Linux, etc.). All of the other disks are in XDF format; you can make images using the XDFCOPY program found on the Installation Disk, which works under OS/2 or DOS, and also worked in a DOS box under Windows 2000 when I tried. There's also a Linux 'xdfcopy' program available that does the same thing. Making these images is not only a good idea for backup purposes; it's necessary because Virtual PC can use XDF disk images but cannot read XDF disks directly from the floppy drive (this feature isn't documented anywhere; I only know it thanks to Ben Armstrong mentioning it on his blog!)
2. Make a copy of the Disk 1 image, because you'll need to make some changes to it.
3. Overwrite the file IBM2SCSI.ADD on the Disk 1 image with blank or very small contents. You can do this by booting DOS / Windows / OS/2 under VPC, inserting the disk image, and then at a command prompt, type "COPY CON A:\IBM2SCSI.ADD", type a few random letters (this may or may not be necessary), then press CTRL-Z then Enter. This will leave enough free space on the disk for the next step. It will also, of course, make the SCSI driver unusable, but it's not usable under Virtual PC anyway (Don't actually delete any files; the installer will complain if you do.)
4. Optionally, remove the line "BASEDEV=IBM2SCSI.ADD" from CONFIG.SYS; this isn't necessary, but if you're a perfectionist, it'll remove an annoying error message that appears for about 1 second :)
5. Overwrite the files IBM1FLPY.ADD, IBM2FLPY.ADD and XDFLOPPY.FLT with newer versions. If you already have OS/2 Warp 4 installed under Virtual PC, you can find suitable versions in \OS2\BOOT. I took the files from an already-installed Warp 4.5.2; files from Warp 4.0 or eComStation will probably work but I haven't tested them. If you have a newer version of OS/2 but it's not installed, the files can probably be found on the installation disks or CD. If you don't have a newer version of OS/2, maybe these drivers can be downloaded from IBM's web site somewhere... and maybe versions from Warp 3 with a late FixPak will work... but I only know about what I tested :)
6. Install OS/2 Warp 3 from the disk images, using the newly modified Disk 1 in place of the original, and installation should proceed as normal. If it doesn't, try different versions of the files in step 5. Once it's installed, follow Ben Armstrong's instructions (http://blogs.msdn.com/virtual_pc_guy/archive/2004/12/07/277467.aspx) for video drivers etc.
Thanks to:
* Ben Armstrong (http://blogs.msdn.com/virtual_pc_guy/) for mentioning that Virtual PC supports XDF - which prompted me to test an XDF disk image under Warp 4.5 and find that it worked there - otherwise I would have assumed that the problem was XDF itself, when it's actually Warp 3's drivers for it.
* Michal Necasek (http://pages.prodigy.net/michaln/) - his report of replacing IDE drivers with those from the Device Driver Pak to make OS/2 2.1 install inspired the idea of doing something similar with the floppy disk drivers.
