Coping With The DOS Software

When loading DOS drivers for your Zip or Jaz drives, you generally have 2 options. You can either use Iomega's Guest.exe utility which can be loaded from Autoexec.bat or entered at the command line, or you can use the Iomega SCSI Software for DOS (for SCSI, IDE/ATAPI, and parallel-port drives) with which the drivers would load from Config.sys (with a couple of SET statements in Autoexec.bat). If you use other drivers (or a BIOS) to get your drive recognized, then Iomega's DOS utilities (SCSIUTIL.EXE) will not function on the drive.

USB drives will not work in DOS because there are no DOS drivers for them.


Each type of drive uses a different ASPI manager depending on exactly what kind of interface it is connected to (IDE, SCSI, or parallel port); and in the case of the IDE drives, whether it's an ATA or ATAPI drive. Because they all use ASPI managers, even the parallel-port and IDE drives are sort of like virtual SCSI devices. Keep this in mind while reading Iomega's instructions (e.g. Manual.exe), and they will be much easier to understand. When they talk about Iomega SCSI software, what they're talking about applies to all kinds of Zip/Jaz drives (except USB). So even if you don't have a SCSI drive, don't just skip over the sections that talk about SCSI because they might apply to your drive as well.


Guest.exe can be run from the command line, or it can be loaded from Autoexec.bat (or even Dosstart.bat when using Win9x's Restart the computer in MS-DOS mode - depending on how you have that set up).

The most common problems involving Guest.exe are related to the settings in Guest.ini which cause Guest.exe to scan for ASPI managers that have already been loaded from Config.sys and to load a number of them on its own while searching for Iomega drives on your system. It's a good idea to edit Guest.ini (with a text editor) to prevent it from doing any more than is necessary for your system. Read about Express Loading Guest in the Guesthlp.txt file.

One advantage of Guest.exe is that its ability to be run from the command line means that you can load the drivers for your Iomega drive(s) after the computer has already finished booting. This is handy when using the drive temporarily on a system; you won't (necessarily) have to alter its Config.sys or Autoexec.bat files to load the driver(s).

Another possible advantage of using Guest.exe is its letter= option with which you can specify the letter that is assigned to the first drive to which Guest.exe gives a letter. But be aware that the LASTDRIVE statement in Config.sys must specify a letter that is at least one later than that used with letter=, so this precludes using Z: for a Zip drive in DOS (there is no letter after Z). If you really want the drive to be Z:, you can use the DOS SUBST command after the drive has already been assigned another letter. However, there are some drawbacks to using SUBST; see the DOS help file for more information.

If you want to use Guest.exe on a permanent basis, it should be loaded from the Autoexec.bat file. See Guesthlp.txt, Manual.exe, and Refman.exe for more information on Guest.exe.

The Iomega SCSI Software For DOS

To install the Iomega SCSI Software for DOS, run the Install.exe file in the Dosstuff directory of the Tools disk (or you can install it from a downloaded file). This will install the software into an Iomega directory on the HD. You'll now have the option of loading drivers from Config.sys instead of using Guest.exe, and you'll have the DOS utility, SCSIUTIL.EXE.

I suggest that you don't allow the installation to alter your startup files as it is likely to add things you don't need. Let it write its changes to Config.iom and Autoexec.iom so you can see what it would have done, and then edit your actual startup files (Config.sys and Autoexec.bat) to include what you actually need for your system. That would go something like this:

In Config.sys...
REM {Load the appropriate ASPI MANAGER as determined by your drive type}
REM {If you have multiple Iomega drives of different types, you'll need to load an ASPI manager for each type}
In Autoexec.bat...

This can become more complicated - particularly if you have a SCSI Zip or Jaz drive in addition to other SCSI drives. Read about the various ASPI Manager Options and the section on Special Information for Users of Adaptec EZ-SCSI in Manual.exe.


This is Iomega's DOS utilities; it's analagous to a "no-frills" version of the Win9x software. It allows for formatting, using the write and read/write protection features, making a drive nonremovable, viewing the Disk Life and Format Life percentages, and a number of other things (see Refman.exe for more information). If you want to format a Zip/Jaz disk in DOS mode, this is what you should use (although Refman.exe will tell you that you can use the DOS FORMAT command on a disk that has already been formatted with Iomega's software).

Files Needed For A Boot Floppy

If you want to make a self-contained boot floppy (which doesn't load any drivers from your HD) that allows you to access your Zip/Jaz drive(s), the files you'll need will depend on whether you want to use Guest.exe or the Iomega SCSI Software.

[When Using Guest.exe]

Put Guest.exe, Guest.ini, and all ASPI managers and .ILM files that Guest.ini tries to load in the same directory on the floppy.

If you have a SCSI drive, then the ASPI manager for your SCSI controller will also need to be on the floppy (if it's a non-Iomega controller, it won't be listed in Guest.ini; but you can add it there instead of loading it from Config.sys if you want).

[When Using the Iomega SCSI Software]

You'll need whatever ASPI manager is required for your drive. And you should have SCSICFG.EXE, SCSIDRVR.SYS, and (I think) all the *.AT, *.OP, and *.DT files from the Iomega directory (I believe SCSICFG.EXE uses these when scanning for drives) in the same directory on the floppy . You may also need the SCSI.SCF file there; I'm not sure whether SCSICFG.EXE will create it from scratch (it'll need to be there eventually as SCSIDRVR.SYS uses it).

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