[Alex Ethridge]

I know Windows 98 will not support 48-bit addressing; but, what about DOS 7? Is there documentation anywhere that explains its limitations (if any) concerning drives larger than 137 Gigabytes?

[JohnWill]

All you ever wanted to know about LBA48, including level of support for all Microsoft software versions: http://www.48bitlba.com/index.htm

[Alex Ethridge]

Lots of interesting information there. Beyond FDisk, though, they don't discuss DOS of any version. But, if FDisk will set up a 300-Gig partition and Format will format it in DOS 7, it would seem DOS 7 supports 48-Bit addressing. That's my own experience, not something I got at the link.

I also found a ten-dollar, 48-Bit addressing support module for Windows 95, 98 and ME. If it really works, it might come in handy.

Thanks.

[JohnWill]

I believe the reason they don't discuss DOS of any version is that it's not supported in any version. Actually, since DOS uses the INT-13 interface of the BIOS for disk operations, the BIOS support for LBA-48 is what's a key to using it with DOS.

I knew of 3rd party LBA-48 drivers, but I've moved on from W9x and WME, so my interest was not significant.

[Alex Ethridge]

It looks like DOS and 48-bit addressing, when supported by the BIOS, get along okay; but, the 48-bit support I got from Rudolph Loew at http://members.aol.com/rloew1/ for Windows 98/ME has so many cautions and possible unknown program installations that disable it that it would be too easy to make a quick catastrophic mistake.

It's an interesting subject, though, at least to me.

Thanks again for the link.

[JohnWill]

I'm hoping that I never have to know or care if MS-DOS supports large disks.

[Alex Ethridge]

Although I have customers who are still running Windows 98/ME, none of them need to address drives that large. It is more a tinkering thing for me than anything else.

I do, however, still run Windows 98 as a second OS on all my systems, primarily so I can get and try out DOS applications like Norton Antivirus, F-Prot and a few other DOS applications (and updates for same) for those situations when I do have to scan a FAT32 system for viruses, rootkits, etc.

It is infinitely easier to simply do a virus scan in DOS mode--none of that 'failure to remove/quarantine' crap.

I have two two-inch CDs that are configured to boot into DOS and scan without my having to touch a key. Just put it in the CD drive, turn it on and walk away. I don't even have to wait on it to finish booting.

[JohnWill]

Microsoft Virtual PC is now free for download, works great to try out stuff like this.