DiskDupe Support Guide

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DiskDupe is a legacy technology and no longer fully supported. We have provided information here to help you address common issues. If you are unable to find the answer you are seeking, please contact us at (925) 689-1200 and we will do our best to help you.

Getting Started

System Requirements

Dos version
  • IBM PC or compatible computer.
  • Dos 3.1 or later.
  • 450k free RAM.
  • Hard Disk, RAM Disk or Network.
  • (Auto/AutoPro Only) Mountain compatible autoloader.

Windows version
  • IBM PC or compatible computer that will run Microsoft Windows 3.1 in Standard or Enhanced mode, Windows for Workgroups 3.11, or Windows 95'.
  • An installed copy of Microsoft Windows 3.1, Windows for Workgroups 3.11, or Windows 95'. A hard disk or network with 2 MB free.
  • 4 MB RAM.
The duplication speeds for diskettes copied with DiskDupe do not depend on the processor speed of the computer if the processor in the PC is a 286 or above. Copying times on XT (8086) computers will probably be slower.

Setting Up Your Computer

The Setup menu is where you specify your computer configuration (ie: controllers, drives, disks, etc.). In most cases, you will be able to use DiskDupe right away without changing anything in the Setup menu. If you do change something, your changes will be automatically saved in the configuration file DISKDUPE.DAT, and will affect all jobs that have been created.

The easiest way to set up your computer is to go down each item in the Setup menu. For the basic setup, you would need to access Controllers, Autoloaders and Drives. Below lists a summary of the basic steps to set up your computer with DiskDupe:

  • (Pro/Auto/AutoPro) Go into the Setup menu and select Controllers. Press Auto-Set and DiskDupe will automatically set up your controllers for you.
  • (Auto/AutoPro) Once you have finished setting up your controllers, select Autoloaders from the Setup menu and edit or add the specifications of the autoloader that you will be using.
  • When you have finished setting up your autoloader, select Drives from the Setup menu and press Auto-Set, which will automatically set up your drives for you.
  • Before closing the Drive List dialog box, click on Test to check your computer setup. If no error messages appear, you are ready to begin duplicating.


These are the three types of installation that you can do. Please Note: It is not possible to run DISKDUPE.EXE from a floppy drive.

Hard Disk Install

To install DiskDupe on your hard disk:

  • Make a subdirectory for DiskDupe on your hard disk by typing the line MD C:\DISKDUPE [Enter].
  • Type CD C:\DISKDUPE [Enter] to change to that directory.
  • Insert the DiskDupe program disk in drive A:, or the appropriate floppy drive, and type: COPY A:\*.* [Enter] to copy the files to your hard disk.
  • Type DISKDUPE [Enter] to load the DiskDupe program.
DiskDupe searches the current directory and your path for its configuration file DISKDUPE.DAT. If you add the \DISKDUPE subdirectory to the statement in your AUTOEXEC.BAT file, you will not need to change to the \DISKDUPE subdirectory every time you run DiskDupe.

Network Install

Running DiskDupe on a network allows you to take full advantage of the multi-user environment and allows you to share image files with others on the network. As long as only one computer is using DiskDupe at a time, you can install DiskDupe on the network under terms of this license agreement. If more than one person will be using DiskDupe at once, contact us for information on site license.

If you are the only one using DiskDupe on your network, you can install it as described in the hard disk installation section. However, if you would like multiple workstations to be able to access DiskDupe, the network administrator should install it according to the following instructions.

Copy all the files from the DiskDupe disk into a shared subdirectory on the network. Run DiskDupe once from that directory to create a DISKDUPE.DAT file.

Copy the file DISKDUPE.DAT from the shared subdirectory to a local subdirectory that DiskDupe will be started from.

DiskDupe searches the current directory and the path for its configuration file DISKDUPE.DAT, which is updated with DiskDupe's current settings each time you exit. if DiskDupe cannot locate a DISKDUPE.DAT file, it creates a new one in the directory from which it was started. There are several ways to ensure that a user's configuration will be saved:

Add the local subdirectory to the user's PATH statement.

Keep Auto-set A: & B: on in the shared subdirectory. If started with the shared DISKDUPE.DAT, DiskDupe will start up with the A: and B; drives tailored to the specific workstation's configuration at the time it was turned on or rebooted. This alleviated the need for some users to have a local DISKDUPE.DAT file.

Start DiskDupe from the local subdirectory or create a batch file to do so.

Ramdisk Install

If the computer doesn't have a hard disk and is not attached to a network, you can run DiskDupe off of a Ram drive provided that you have enough memory. DiskDupe can be run off of a hard disk or a Ram drive but it is not possible to run DISKDUPE.EXE off of a floppy drive.

If you only have extended memory you can use a RAM disk to run DiskDupe. Copy the DiskDupe files from the floppy to the RAM disk and run DiskDupe on the Ram disk to leave your floppy drives free for copying.

If you have the Pro edition of DiskDupe a special RAM disk called a RAMBODSK.EXE is included. If you have the Standard edition, you can use the RAMDRIVE.SYS utility included with Dos instead. 

Follow the instructions below to run DiskDupe from a RAM disk.

  • Create a boot-up disk and copy *.sys and DISKDUPE.* from the DiskDupe disk to the boot-up disk with the Dos copy command.
  • Add the line: DEVICE = RAMBODSK.EXE to the CONFIG.SYS file on the boot-up disk. The RamboDisk will be given a drive letter, such as C:.
  • Modify the AUTOEXEC.BAT file to contain the lines: 
  • Run DiskDupe from the RamboDisk C:, configure it as described in the Setup chapter, and exit to save the configuration file.
  • Copy DiskDupe's configuration file, DISKDUPE.DAT, from the RamboDisk in C: to bootup disk in A:. This will preserve your customized setup for future use. If you make modifications in the future, copy the file to the bootup disk once again.

Navigating the Menus

DiskDupe uses the same technique for navigating the menus that is used in Windows, and just like Windows there are pull-down menus available across the top of the screen that allow the user to access dialog boxes for entering selections.

Note: DiskDupe requires that at least one window be open to operate. If you close all the Job windows leaving a blank desktop, you can obtain a list of jobs available by pressing [F3], or by selecting File|Open|Job from the menu bar.
  • If you have a mouse, you can select menu choices by clicking on them with the mouse.
  • If you do not have a mouse, you can select menu choices by pressing [Alt][Z] where [Z] is the first letter of the menu. Once the menus are active, you can move around them using the arrow keys. Use [Enter] to select a menu item.
  • The [F10] key enables the 'Sticky Menus' for default access to the menus for mouseless computers. Press [F10] again to turn 'Sticky Menus' off.
  • Once you have selected a menu item, a dialog box appears with choices for that item. Use [Tab] or [Shift][Tab] to move from field to field. When you have made your selections, press [Enter] to save them.
  • When you are in a dialog box you can press [Alt][N], where [N] is the highlighted letter of the option you want to go to. You can also press the highlighted letter of the option alone to move around as long as you are not moving from a field that required you to type something in.
  • To leave a dialog box press [Esc]. To leave a help screen press [Esc] (Dos only). To close a job or any other file box, either click on the Close button in the upper left corner of the box or press [Alt][F3] (Dos only).
  • In the Help screens you can also use the [Tab] key to move the highlight bar from one keyword to another. Use [Enter] to select the highlighted keyword. Use the arrow keys or the [Page Up] and [Page Down] keys to scroll up and down in the Help screen.

Basic Operation

DiskDupe has two basic operations - Duplicating and Comparing. You can also format disks, which is a variation of duplicating.

Compare or Duplicate Diskettes

Compare checks that two or more disks are identical. Duplicate makes a copy of a disk. The Copies setting controls the number of copies that are made. Enter 0 to copy continuously.

Whether you are duplicating or comparing, DiskDupe always works from the Source to the Destination. It copies from the source, sometimes called master disk, to the destination, or target, disk.

The Source is the location of the master diskette to be copied or compared to the destination chosen for the job to be performed. The Source could be a drive that contains a master diskette, an image file, a set of image files, a RamboDisk or a Dos format. If you are creating a set of images and you have the masters for the set in several drives, set Source to Cascade. If you want to make copies of different master disks without using the keyboard, set Source to Relay.

The destination is the place where you want your source to be copied and/or compared.

Destination could be: 
Image file (to create a new image file) 
Set of image files 

Regardless of the options chosen, DiskDupe makes an exact copy of a disk, including system and hidden files, subdirectories and volume labels. However, DiskDupe cannot make duplicates of copy protected disks.

Format Diskettes

With DiskDupe, you can either format a disk as it is being duplicated or separately. When you copy disks with Duplicate, DiskDupe will detect whether a disk has been formatted and, if necessary, format it while copying. Use Format as a separate feature whenever you want to preformat disks ahead of time for later use with DiskDupe such as making master disks or for general Dos use.

To format a disk separately:

  • Set Source to Format.
  • Set destination to the drive you will use to format the disk and press Ok. This can be one drive or a number of drives using Cascade.
  • Go to the Format and Verify settings. Set the Format and Verify to the appropriate settings.
  • Set the number of Copies, or set it to 0 for continuous copying, and select Duplicate. When you are ready to format, press Go. 


Bad Disks / Unreadable Copies

If DiskDupe produces disks without reporting errors but some of the disks are unreadable there are several possible causes.

DiskDupe has several CRC checks built into it. Every track of the image file has a CRC, and there is a CRC for all of the tracks in the image, so you will find that if one bit of the image is changed in the data area then it will be rejected by our software ("Error 908, Image file corrupted"), so if there were a bad spot on your hard drive we would catch this.

DiskDupe also does a CRC check of its own code loaded in memory ("Error 906, Code Memory Corrupted") and a CRC check of the buffers used to store the image while transferring it to the diskette ("Error 907, Buffer Memory Corrupted").

When DiskDupe is run with "Verify" set to "Always" then every bit written to the disk is read back and compared to the original image and because of the above mentioned CRC checks it is not possible for the data to be written to the floppy with a different bit content from the image file.

Despite all of this checking it is possible for data to get corrupted when read from the floppy controller if there is a DMA problem causing a master to be read incorrectly. Running Drive Test ("Diagnostics") in DiskDupe will catch this and report either Error 205, Bad DMA, or Error 301, Bad Compare. Try running Drive Test to see if errors are reported on this machine.
  • If Drive Test passes then take some of the unreadable diskettes and compare them to their corresponding master disks or images using DiskDupe with the drive that the copies were made in and on other drives as well. Typical error messages that will come up are Error 202(Bad Address Mark), Error 204(Record not Found), and Error 207(Bad CRC). (If DiskDupe were to report an error 301(Bad Compare) reading one of these copies then this would indicate a hardware problem (most likely a DMA conflict) and also that the diskettes were copied with the compare option turned off in DiskDupe.)

If the bad disks are readable in the drive that produced them but not readable in other drives:

  • Poor drive alignment. This is probably the most common cause. If the diskettes are consistently unreadable in most drives except the drive that they were written on then the alignment of the drive used to make the copy is questionable. Usually such a diskette will be unreadable starting with the first track (i.e. cannot read the directory) on other machines. Check the alignment using DiskDupe Pro or AutoPro.
  • Poorly positioned track zero sensor. If the track zero sensor is positioned incorrectly then the drive might be able to produce diskettes that have the tracks in the wrong place on the diskette. Usually such a diskette will be unreadable starting with the first track (i.e. cannot read the directory) on other machines.
  • Copy drive is passing marginal diskettes. This problem is most common with double speed drives, especially Y-E Data 2X and 2XSDS drives. Diskettes that spin at double speed produce a stronger read signal than at regular speed so it is often possible to read a marginal diskette at 2X but not at 1X. Diskettes with these defects will often be readable on the first tracks because their errors (usually due to drop-outs in the media) occur randomly on the diskette. This problem is most obvious when poor quality media is used. Try reducing the number of retries that DiskDupe allows when comparing the disk to zero by using the /retries# command line switch (i.e. call up DiskDupe by typing: DISKDUPE /RETRIES0 from the Dos prompt. This setting gets saved in the DISKDUPE.DAT file so it does not need to be set every time. The default number of retries is two. This command line switch is only supported in version 4.09 and above and only in the Pro and AutoPro versions.
  • Disk type is set incorrectly in DiskDupe. This problem can be avoided by leaving the disk type set to "Auto" in DiskDupe. For example if you are making disk-to-disk copies of 1.44Mb disks with the disk type set to 1.2Mb then DiskDupe will read the master disks as it were a 1.2Mb diskette (ignoring the last three sectors of each track). The disks produced will be completely unreadable (fail on the first track with a "Record not found" error).

It the diskettes are not even readable on the drive that wrote them:

  • Dirty Drive heads: Before checking anything else make sure that the heads on the drive are clean because dirty heads are unpredictable.
  • Poor media quality: In this case the bad disks will show errors on various tracks. If the diskette quality is poor then the diskette will not hold its signal well over time. Use only certified diskettes with a clipping rate of at least 60%. For best results use blank media and format them as you copy to them using DiskDupe with "Format" set to "Always" in the Setup menu.
  • Drive cable is loose: If the drive cable connector is loose and pins 32, 33, and 34 are not connected and the rest are, then DiskDupe will format, write and verify disks with compare on, but the disks will be bad. It will also format the disks even if they are preformatted.Pin 32 is the pin that selects which side of the disk gets written to. If it is not connected then all of the data will be written to and read from only one side of the disk. When copying the disk DiskDupe reads back the information that it writes for each track immediately after writing it and thus reports no errors despite the fact that all the data is being written to and read from only one side of the disk. For each track the data for the first side gets written to and read from the first head and then the data for the second side gets written to and read from the first head again.If these disks are compared in a separate pass after duplication then DiskDupe will report and Error 204(Record not Found) on the first track since all of the side 1 data has been overwritten by the side 2 data. Drive Test will report the same error.
  • Diskette has not been removed from drive after copy: DiskDupe gets its speed by bypassing Dos and the BIOS of the computer. In doing so Dos is left in the dark with regards to the changes that occur to the diskette while the DiskDupe software is running. This often leads to strange results when a directory command is tried immediately after exiting from DiskDupe. If the diskette is removed from the drive and a [Ctrl][C] is typed before reinserting the diskette then Dos should then recognize that the disk in the drive has been changed and give an accurate response to a DIR command.

DMA Problems and Troubleshooting Steps

If you are getting a "205 Bad DMA" go to step 1.

If you are getting a "212 SDS Head 1 Bad DMA" go to step 4.

Trouble-shooting Steps
  1. Perform a drive test (see NOTES) with a low density (720K) disk. If a DMA error still occurs, skip to step 3.
  2. Change the bus speed (see NOTES) in the CMOS setup of the computer and perform a drive test with a high density (1.44MB) disk. Continue this process until the DMA problem is gone or there are no more options to change. Skip to step 6 if this doesn't fix it.
  3. Change the DMA channel (see NOTES) that your floppy drive controller is using for drive head 0. Repeat this process until there are no other DMA channels to choose.
  4. Change the DMA channel (see NOTES) that your floppy drive controller is using for drive head 1. Repeat this process until there are no other DMA channels to choose.
  5. Remove all non-essential adapter cards from your PC, especially network and sound cards, perform a clean boot (see NOTES) and go to step 3.
  6. Disable the computer's cache from the computer's CMOS Advanced Chipset Setup Options.
  7. Try using another computer, preferably a different brand. The DMA chipset, that is on the computer's motherboard, is probably not compatible with DiskDupe's high-speed data transfer (see Notes).

How to Perform a Drive Test

The DiskDupe drive test feature is an excellent method for diagnosing a setup problem.

Run DiskDupe and go to Setup|Drives menu, highlight the drive with the DMA problem, and type "T" for test.

How to Change the Bus Speed

Sometimes the bus speed of the computer may be too slow for the fast DMA rates that DiskDupe uses. Most people do not realize that the bus speed of the computer does not depend on the processor speed. A 166Mhz Pentium can still have a slow bus speed.
  1. Reset or turn off/on your computer. While the computer is booting look for instructions on entering your computer's CMOS (for most computer's pressing the [DEL] key will take you to a CMOS menu, on others it is the [F1] key).
  2. From the CMOS menu, select either Advanced Chipset Setup or Chipset Setup (the terms will vary depending on the BIOS manufacturer).
  3. From the Advanced Chipset Setup or Chipset Setup menu, look for options like: Bus Speed, Bus Wait States, DMA speed or I/O Recovery Time that can be changed. Change one option at a time trying all the possible combinations available, even values that might slow the bus speed down. Depending on the item being changed, its value may be expressed as a "CLCK/X" (Clock divided by X) expression. The higher the "X" value the slower the speed, and the lower the "X" value the higher the speed. Continue this process until you have exhausted all methods for altering the bus speed.

How to Change the DMA Channel

A DMA conflict can occur when there is a conflict between the floppy controller and some other device in the computer that is using DMA. One solution is to try changing the DMA channel that your floppy drive controller is using
  • If you have an Allegro I SDS controller card you can jumper the card to use DMA channel 1, 2, or 3.
  • If you have an Allegro II card, the DMA channels can be chosen from within DiskDupe under the Setup|Controllers menu and can be changed to 0, 1, 2, or 3. Remember if you have an SDS drive, you will have to select two different DMA channels.

How to Perform a Clean Boot

A clean boot is an excellent method for determining whether a device driver or TSR is causing a problem, since the computer is booting without them loading.

To perform a clean boot with Dos 6.0 or later:

Reset or turn off/on your computer. While the computer is booting, press the [F5] key when the computer says "Starting MS-Dos".

To perform a clean boot with Dos 5.0 or earlier:

Make a bootable floppy disk first by formatting a disk with the "FORMAT A: /S" from the Dos prompt.
Insert the bootable floppy into your drive a: and reset or restart your computer. Your computer will now boot from the floppy disk instead of your hard disk.

DMA Chipset Incompatibility

We have observed that with certain computers that the DMA controller, which handles DMA transfers and DMA requests, will sometimes send an additional byte of data during a block transfer. This additional byte means that the data in memory will not compare to the original data, which produces an error.

If you have tried everything, and you are still experiencing DMA problems, then the DMA chipset that is on the computer's motherboard may not be compatible with the high-speed data transfer that DiskDupe performs. Our recommendation is to try using another computer, preferably a different brand.

Error Messages