ADTWin 1.4


ADTWin is a free tool for writing Amiga disks from a PC. It requires a Windows PC with a parallel port and a floppy disk drive that is connected to the PC's parallel port by a self-made cable. The disk content has to be provided in form of an Amiga Disk File (there are lots of ADFs containing Amiga games and other software out on the web) or raw MFM file. Only the original double-density disk format is supported, however, HD disks can be used. The write process is about as fast as on the original Amiga (≈40s per disk using appropriate PC hardware). It is not possible to read disks.

This manual mainly covers the basic usage of ADTWin. To download the latest version of the tool, to get detailed instructions on constructing the cable, to get important troubleshooting hints and other information about using ADTWin or to give feedback, please visit the

ADTWin web page

Building the cable

To use ADTWin, you need a special cable that connects a floppy disk drive to your PC's parallel port. It can be constructed from a (female) 34-pole insulation displacement connector (IDC), a 34-pole ribbon cable and a (male) 25-pole D-SUB connector. The pinout is specified in the table below. Connector pins that are not mentioned in the table remain unconnected. Detailed information on how to build the cable is provided on the ADTWin web page.

FDD connector (IDC) pin
Parallel port connector (D-SUB) pin
FDD function
Parallel port function
18 5DIR
20 6STEP
32 9SIDE1

Setting up ADTWin

ADTWin does not require any installation procedure. But, depending on your system, some or all of the following steps might need to be taken before you can use ADTWin.

Deactivate signature enforcement (for 64 bit editions of Windows Vista or later versions)

When running a 64 bit edition of Windows Vista or a later Windows version, you have to disable driver signature enforcement before you start ADTWin. For Windows Vista/7, the easiest way to do so is to press F8 on boot-up to enter the advanced boot options menu and select the corresponding option. For Windows 8.1/10 you have to use the recovery options to activate the advanced boot options. Another possibility is to permanently activate Windows' test signing mode. The ADTWin web page contains detailed hints on this topic.

Run as administrator

ADTWin must be executed with administrator privileges. Under Windows XP it is sufficient to be logged in with an administrator account. Under Windows Vista or later Windows versions, you furthermore have to start ADTWin by selecting "Run as administrator" from the context menu of the ADTWin.exe file. Alternatively, you can enable the "Run this program as administrator" property, found on the "Compatibility" tab of the "Properties" dialog which can be opened from the context menu. After that, ADTWin.exe will always run in administrator mode when you start it.

Using ADTWin

Before you start ADTWin, close all other applications that might use the parallel port or cause other activity that might interfere with ADTWin (e.g. soundcard activity, if you use ADTWin with a parallel port PCI card). Then simply double-click the ADTWin.exe file found in the ADTWin folder. Under Windows Vista or later, you have to run ADTWin.exe with the "Run as administrator" option (see above) and might see one or two requesters that have to be confirmed. They remind you that ADTWin might make changes to your system and uses an unsigned driver.


If you have more than one parallel port, you need to select the port to which your disk drive is connected from the drop-down list in the "Port" field. The list should show all native and PCI/PCIe-card-based parallel ports that are available in your system. A requirement for a PCI- or PCIe-card-based parallel ports to be detected by ADTWin is that the card's driver is installed. If, for any reason, a parallel port is not shown in the list, it can be explicitly specified by calling ADTWin from the command line with option "-port", followed by the hexadecimal base address of the port. The base address can be found on the LPT device's "Resources" tab in the device manager. It's the start address of the first or second "I/O Range" setting. You should use the "-port" option in conjunction with option "-lpt" to specify the LPT device number of the corresponding port, if it is exposed as LPT device.

Connection Mode

Most floppy disk drives that are used in a PC are configured as "Drive B" which is the default selection of ADTWin. If your disk drive has been used as one of two drives on an FDD cable w/o the "7-wire-twist", it might be configured as drive A. In this case you can simply switch the connection mode to "Drive A". If you want to use the Amiga's internal disk drive, then select connection mode "Amiga drive". Further hints on using the Amiga's internal drive can be found on the ADTWin web page.


Write precompensation is an advanced issue. If you do not experience any problems when writing Amiga disks and no read errors occur when using them on the Amiga, then simply leave the precompensation selection at its default "Generic". In case of problems like weak write timing accuracy you should switch precompensation off. Have a look at the troubleshooting section on the ADTWin web page for further hints.
For users who want to use custom settings for the write precompensation, here is a short description: When reading from a magnetic disk, the time between neighbouring flux changes can appear differently than has been scheduled when writing. This can increase the probability for read errors. To alleviate this problem, the effects of neighbouring flux changes can be anticipated at write time by shifting the write pulses by a short offset forth or back in time. The optimal setting for this precompensation time mainly depends on the hardware properties of the disk drive that is used for reading the disk and on the bit density of the written track (inner tracks need more precompensation than outer tracks). To specify the precompensation times manually, activate the "Custom" setting and enter (at most 10) comma-seperated cylinder/time pairs. The cylinder number can range from 0 to 79 and the time is specified in nano seconds. The mentioned cylinders get the designated write precompensation, intermediate cyclinders are interpolated. For example, the setting "0,50,79,200" determines a write precompensation time of 50ns for cylinder 0 and 200ns for cylinder 79. Cylinders 1 to 78 get an interpolated time between 50ns and 200ns. If the first precompensation time is specified for a cyclinder greater than 0, then all lower cylinders get the same precompensation time. Similarly, if the last mentioned cyclinder is lower than 79, then all greater cyclinders get the time of the last mentioned cyclinder, too. For example, precompensation setting "19,0,20,100,39,100,40,200,59,200,60,300" assigns 0ns to cylinders 0-19, 100ns to cylinders 20-39, 200ns to cylinders 40-59 and 300ns to cylinders 60-79.


After clicking the "Test" button, ADTWin performs some checks in order to figure out whether or not writing Amiga disks will probably be possible. You can perform this test without having a disk drive connected to the parallel port to find out whether your hardware is appropriate for writing Amiga disks before constructing the connection cable. Note that this test can only cover some aspects of the disk write operation. Despite a positive result you cannot be entirely sure that writing Amiga disks will work. If the test reveals that writing Amiga disks is not possible or the performance will be weak, consider the troubleshooting hints on the ADTWin web page. If you still get a negative result, then writing Amiga disks does probably not work on that system.


Clicking the "Add..." button opens a dialog that allows selecting one or more Amiga disk files (*.ADF) or raw MFM files (*.MFM, see below) that shall be written to disk. The selected files are displayed in the file list area on the left side of the main window. The list can be cleared by clicking the "Clear" button.
Instead of using the "Add..." button you can also drag and drop single or multiple files or directories into the ADTWin window in order to add them to the file list. Directories are filtered for *.ADF and *.MFM files and are not scanned recursively.
If an appropriate extract script is provided (see below), then files contained in archives can be added, too.


Clicking the "Start" button starts the write process. The Amiga disk files listed in the file list area will be written to disk one after each other. After one disk has been completed, you will have to change the disk and confirm to proceed. If you did not execute the test by clicking the "Test" button (see above), then the tool will perform the test automatically before starting to write the first disk. During the write operation your mouse may get stuck. This is a consequence of Windows being freezed during the write process which is necessary to keep the write process free of any interference by other system activity. You can abort the write operation by pressing the ESC key.

Extract script

To put ADTWin in a position to process file archives (e.g. "*.zip" files) that contain Amiga Disk Files, the user may provide a Windows batch script with name "Extract.bat" in the ADTWin folder that extracts the files from the archive. Whenever ADTWin encounters a file with unknown suffix among the files to be added, it calls the extract script and adds the extracted files, if any, instead. A template script can be found in the ADTWin folder.

MFM files

Apart from Amiga Disk Files that can only contain images of disks in Amiga disk format, ADTWin can write raw MFM data to disk that is provided by means of an MFM file (*.MFM). The file must contain either 160, 162 or 164 tracks. Each track is made up of exactly 12864 MFM bytes, including the track gap at the beginning. A conventional Amiga disk track, for instance, would look like this: 892 MFM-coded zero bytes (0xAA), 11 * 1088 MFM-coded data bytes, 4 MFM-coded zero bytes (0xAA)
The MFM file simply consists of the concatenated MFM-coded track data in ascending order of track numbers, without any header or meta data.

Command line options

ADTWin has a few command line options. Run ADTWin.exe from a Windows console with command line option "-h" to see the usage information. For most users it is not necessary to use any of the command line options.


ADTWin is free for non-commercial use. Distribution, modification or use for commercial purposes requires a written permission by the author. Find more information on the ADTWin web page.
ADTWin comes without any warranties or conditions. The author cannot be hold liable for damages caused by using this software, including, but not limited to, hardware defects and loss of data.

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