I have an Iomega 80GB (one month old) USB external hard drive that is identified both in Windows and in DOS as a WDC WD800B-JHA0. I connect it to a laptop using Win98SE and to a desktop using Win98. Under Windows the drive functions fine using EHCI USB2 ports. For real DOS I use an emergency boot floppy with the pair of drivers USBASPI.SYS v2.15 and DI1000DD.SYS v2.0. The drive worked fine on both the laptop (EHCI) and the desktop (UHCI - had to use the motherboard USB1.1 ports with an intel chip). Attempting to construct an emergency boot CD with USB support, I had to experiment with other drivers (ASPIUHCI.SYS + ASPIDISK.SYS and DUSE.EXE) but had no success. Worse when I went back to real DOS using the floppy the system could not read the disk directory/file structure. DIR reports the volume serial number and the correct drive size but only a file RRaA of 0 bytes and no directories. It seems DIR is interpreting the FAT FileSystemInfo sector initial string RRaA as a file name and then nothing else. Same result on both machines. The drive continues to function fine in Windows and protected DOS as before. Scandisk and Fdisk/status report no problems and the drive as an active single (unpartitioned) primary DOS partition. How can I get the DOS functionality back? Any help is appreciated.

Could it have something to do with the fact its an 80GB drive that most likely has an 80GB partition and DOS only support 2GB partitions. Or are you using a Windows 98 version of DOS on the diskette.

If you are wanting support for backup then try www.acronis.com it is Linux based and therefore more mature USB support. If you insist that a DOS solution is the answer then look at: http://www.mwpms.uklinux.net/x86.computers/usbfire.htm and try APSoft's point enablers as they work differently to Panasonic USBASPI drivers.

Yep - MSDOS no see'um FAT32 partitions ( anything >8GB. ) You may not have time to search the Internet for your answer. Well, sorry, I may not either.

Regained DOS recognition of 80GB USB External Hard Disk Drive (EHDD) Systems, USB Hardware/Drivers, EHDD as described in initial post. Although I did know of the MSDOS 8GB partition limit, I blindly followed the OEM admonition against attempting to partition the 80GB drive. It initially seemed wise since I had drive access in both Win98 and in real mode DOS. Currently I do not know why real DOS access initially succeeded! I now understand why the OEM presumed DOS access was not possible (at least they did not want to bother with support) and warned owners not to partition the drive. But hey DOS backup against internal HD failure (when you have more than one machine) is one of the main reason you buy one of these EHDD! Set about to size some partitions at 8GB and immediately encountered the Catch-22 that all partitioning instructions and most software presume operating in real DOS mode. But I could not access the drive from real DOS because the ASPI-LogicalDrive mapper (DI1000DD.SYS or ASPIDISK.SYS) hung if it saw any partition above 8GB in its CHS-LBA calculations. (... snip many hours of experimentation, searching and anguish ...) SOLUTION: 1. Initially use FDISK and FORMAT from within protected DOS mode which is OK when working on a drive that is not the active OS. FDISK suffers from the MS imposed limitations of creating only DOS partitions and allowing only one primary DOS and one extended partition per table. FORMAT in protected DOS mode seems to get an initial primary DOS partition 8GB or less OK, but when doing subsequent partitions on the large drive it got the sizing all wrong. My guess is that protected DOS mode works through the virtual Win drivers and not directly with the BIOS LBA int 13h and therefore gets confused on the CHS-LBA translations. 2. Use PTEDIT32.exe (much more useful than FDISK) to create up to three 8GB primary DOS partitions Type = 0Ch and hide the fourth partition entry from DOS (e.g. Type = 1Ch). Actually you could make this fourth partition extended and continue to create DOS logical drives up to 8GB. If the final partition exceeds the 8GB limit it must be hidden from DOS (and therefore from Windows too - but you can use this remaining space to experiment with other OS). 3. Once the ASPI-LogicalDrive mapper see only drives of 8GB or less it is happy and mounts the drives. Use FORMAT.exe from within real DOS to make the drives accessible for read/write. NB: If you use PTEDIT32.EXE, there is a nice help file by Dan Goodell at http://www.goodells.net/multiboot/ Be careful to note the 1023 cylinder limit (important so the editor doesn't choke but unimportant in LBA) and the start head cylinder 1 for the initial partition entry in any table due to the 63 hidden sectors. Thanks to the above respondents.

i am putting a internal 20gb drive on my p2 400mhz comp. i have msdos 6.22 and win 3.1. My answer is: what is the biggest partition msdos can support?, and if it cant support 20gb, is there a dos os that can? Ratboy