IDE/ATAPI Zip Drives

Different Types Of IDE Zip Drives

There are at least four different kinds of IDE Zip drives - the original ATA version, the ATAPI version which replaced it, an ATAPI2 version which seems to have replaced the original ATAPI Zip, and an ATAPI3 version which will probably replace the ATAPI2 . The various types of IDE Zip drives can be differentiated in the following ways:

Note that different types of IDE Zip drives use different jumper settings, so it's important to know which type you have.

My experience is with the ATAPI drives, but I think most of this information would also apply to the older ATA drive.

I think you can download the manuals for the original ATAPI Zip drive from Iomega.

The manuals for the ATA Zip seem to have been removed from Iomega's website. I think the main difference in configuration is the jumper settings, so I've included the relevant illustration from Iomega's PDF file here.

The ATAPI2 Zip has some special configuration issues - especially when it's set for drive A: mode. You can find some ATAPI2-specific information here.

I'm told that the ATAPI3 Zip no longer supports drive A: mode as the ATAPI2 model did. Apparently, Iomega decided that it was more trouble than it was worth.

Connecting The Drive

I think it's usually best to connect an IDE Zip drive as master on the secondary port. Slaving a Zip drive to a CD drive may cause problems because some CD drives don't support a slave drive properly (among other things, it seems that this can cause the hard disk access light to remain steadily lit). While an IDE Zip may work OK on some systems when slaved to a CD drive, there are times when it won't. The configuration with the least potential for trouble would be to make the Zip master on the secondary port.

Since Zip drives are jumpered for slave by default, you will need to move the jumper(s) to the master setting when connecting one as such.

The System BIOS

The most common problems with these drives are BIOS related. And the most apparent symptom of a BIOS problem is usually the appearance of a "phantom" B: drive in Win9x that causes the system to hang when accessed. If a computer has a system BIOS that is not compatible with the Zip drive (a compatible BIOS would probably mention the Zip by name in its settings), and if there is no way (using the computer's CMOS setup utility) to prevent the BIOS from attempting to control the Zip drive, then that's going to be a problem.

Note that a compatible BIOS is still likely to display a message during the boot process indicating that it found the Zip drive (even with the BIOS set at "None" or "Not Installed" for it), but it shouldn't cause any problems if it is actually compatible.

If a BIOS problem occurs, then try using the system CMOS setup utility to tell it that there's nothing connected where the Zip drive is installed (e.g. secondary master). Set it to "None" or "Not Installed" if such a setting is available (you can do the same for an IDE CD drive if you have one). Some people have reported that they needed to select a "User" setting before their BIOS would leave their Zip drive alone - maybe choosing bogus settings like all zeros would cause the BIOS to reject the Zip drive. You may need to experiment with this since there are many different BIOSes and BIOS revisions. If you are unable to prevent the BIOS from taking control of the Zip drive, then upgrading the BIOS might help. Or you could connect the Zip to an add-on IDE port that isn't subject to BIOS control (sound cards often have one).

VIA Chipsets

Motherboards which use certain VIA chipsets may not work properly with some ATAPI Zip drives. There is an Iomega document which discusses the problem. Also, see VIA's website.

Windows 95/98 Issues

[Real-Mode (DOS) Drivers]

Generally, Windows 9x works best when you're not loading any DOS drivers from Config.sys or Autoexec.bat. If you haven't read THIS, then you probably should. If you want those drivers for when you Restart the computer in MS-DOS mode, then there are better ways to load them. I think the best way is to edit the Exit To Dos PIF file in the Windows directory so that it loads everything you need for DOS mode from its Config.sys and Autoexec.bat boxes (as if from a floppy boot disk) which are enabled when you Specify a new MS-DOS configuration. See these Microsoft Knowledge Base articles for more info:

General Tips for Using MS-DOS Mode
Description of Restarting Computer in MS-DOS Mode

[Busmastering Drivers And The Registry]

If you have incompatible busmastering IDE drivers installed in Windows 9x, you're likely to have problems with your IDE Zip drive. A common symptom of this would be that your drive reports something like a 400MB capacity and just doesn't work correctly (if at all). Some have even reported a "phantom" B: drive which is usually a symptom of a BIOS problem.

If you encounter such a problem, You could either uninstall the busmastering drivers or you could try hacking the Registry to force the secondary IDE port (with the Zip) to use the default driver. Before editing the Registry, it's always a good idea to back up the System.dat and User.dat files - just in case.

If you want to try hacking the Registry, start Regedit.exe, and look here:


Find the entry that corresponds to the IDE port that the Zip is using (read the DriverDesc for each one). If you find that it's using a PortDriver other than esdi_506.pdr (e.g. ideatapi.mpd), then change it to esdi_506.pdr.

Then, look here:


If you find a NOIDE entry there, delete it.

[Windows 95 Driver Requirements]

If you have a version of Win95 earlier than Win95B (aka OSR2), there are some drivers that are likely to need upgrading. Using Explorer, find esdi_506.pdr and voltrack.vxd in the Windows\System\Iosubsys directory. Find the version for each by right-clicking on it, selecting Properties, and viewing the File version on its Version tab. I think you should have at least v4.00.1112 of esdi_506.pdr and v4.00.953 of voltrack.vxd.

If you have older versions of these files, then installing Iomega's software (Tools95 v5.3 or later) should update them for you. Older versions of these drivers do not support removable drives properly (and older versions of Tools95 do not support IDE Zip drives properly). If you don't want to install the Iomega software to update them, it can be done via Microsoft's REMIDEUP.EXE file.

[Device Manager Settings]

View the Properties/Settings for the Zip drive in the Disk drives section of Device Manager. Disconnect, Sync data transfer, and Removable should be checked there. No other boxes should be checked. If you want to check Auto insert notification, you can. This will cause an Explorer window to open displaying the contents of the Zip disk whenever you insert one. However, if you use read/write protected Zip disks, this will generate an error message when inserting one.

If you find that Int 13 unit is checked and greyed out, then I think that means the drive is under BIOS control. This may or may not be a problem depending on your system BIOS. If you can uncheck Int 13 unit, then do so, and reboot the computer. If you find it checked again after rebooting, then don't worry about it if things seem to be working correctly.

I've been told that the Zip 250 supports DMA, so you can try checking that if you have a Zip 250. It can reduce the load on the processor while the drive is being accessed. Don't try it with a Zip 100 though; it doesn't support it.

DOS Drivers

The DOS ASPI manager for the ATAPI Zip drive is ASPIATAP.SYS. But for the ATA Zip drive, it's ASPIIDE.SYS. Make sure you use the correct one for your drive.

In some cases, an IDE Zip drive will be assigned to B: (or A: if there is no floppy installed) in DOS without loading any drivers for it. If you find this to be the case on your system, then you probably shouldn't try to load any drivers for the drive; just use it with the assigned letter.

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