This document explains how to:
- Create an HDF disk image of an Amiga disk drive attached to a Windows
PC, which can then be used both as a backup and in Amiga Forever
- Attach any SCSI or IDE device to a Windows PC and use that directly in
The two approaches are complementary: if
you create a disk image, which is the
recommended method for using Amiga disk data
on the PC, you do not need to follow the
lower-level SCSI access instructions.
Alternatively, if you need to transfer data from the Amiga to a
Windows PC and you prefer not to attach the disk drive itself to
the PC, you can consider using Amiga
Important: Because Amiga SCSI devices and
media are generally quite old, we recommend that you copy your
Amiga data to new storage media as soon as you are able to
access it. If possible, prepare the required interface and
software first, and then switch on your legacy hardware only
once, and immediately proceed with the transfer.
These instructions were
written for Amiga Forever 2012. Special thanks to Toni Wilen for assisting in the preparation
of this document. Thanks also to Microsoft for their assistance
in implementing low-level SCSI passthrough
functionality, which is a feature that is
rarely seen even in high-end emulation
Recommended Approach: Using Disk Images
Windows software like
WinImage (free trial) can
be used to create an HDF image file of an Amiga disk connected
to the PC. To run these applications it may be necessary to right-click and
manually select Run as administrator.
Benefits of this procedure:
- Aging hardware needs to be read only once (lowest possible risk of
- Supports different types of media (hard disks, magneto-optical disks,
SyQuest cartridges, Iomega ZIP drives, etc.)
- The host operating system (Windows) does not need to have an Amiga file
- The resulting disk image can be mounted in Amiga
To create the disk image:
- Install the imaging software (e.g.
WinImage) and test the entire procedure
on some non-important disks if possible
- Connect the disk to the PC (follow the device-specific instructions,
switching off the PC if necessary)
- Do NOT mount the Amiga disk assigning it a Windows drive letter
or expect it to appear under the Computer folder, but rather make sure that
the disk is listed in Disk Management (select Computer Management from the
Windows Start menu, then expand the Storage folder on the left, and click
on Disk Management)
- If using SelfImage, configure the Input to come from a drive and the
Output go to go a file, with no Processing (compression) options. Select
the desired drive (use the "entire disk" option) as the Input Location.
Select any file name you wish as the Output. After imaging is complete you can
rename the resulting .img file "amiga.hdf" or any
other name ending in ".hdf".
- If using WinImage: select "Creating Virtual Hard Disk image from
physical drive" from the Disk menu (you may have to tick "[x] Include non
removable hard disk(s)"), then "Create Fixed Size Virtual Hard Disk", then
"OK", then in the Save As dialog select "Save as type: Image File (*.ima)"
instead of the default (*.vhd). You can name the file "amiga.hdf" or any
other name ending in ".hdf".
- Make a backup copy of the disk image and archive it in a safe place
Additional steps for a more rigorous,
- Create the disk image using a USB
write blocker, a disk controller with a
read-only mode, or similar solution to
prevent writes to the media being imaged
- Immediately calculate a secure hash
of the disk image file (e.g. SHA-256 or
- Timestamp and/or publish the hash
(e.g. on Twitter)
- Video-record and/or have witnesses
for the entire procedure
To mount the disk image in Amiga Forever:
- Decide where to save the .hdf file. For example, you can select
Open/Amiga Files from the File menu in Amiga Forever, then in the resulting Explorer
window select the "hdf" folder inside "Shared". (This will be
"C:\Users\Public\Documents\Amiga Files\Shared\hdf" or similar depending on
- Right-click the configuration to which you would like to add the disk
image and select Edit...
- In the Media tab of the RP9 Editor, click the Add... button
- Select Type: File and click "..." to select the .hdf file created in
the previous step
- Select Location: Absolute (or Data)
For additional information:
SCSI Devices and IDs (Units)
When the SCSI & IDE option is enabled (in the Configuration tab of the Amiga
Forever RP9 Editor) you
can use one of two devices inside the emulation environment:
- uaehf.device (for hardfiles, "real" hard disks
and other block-type devices);
- uaescsi.device (optimized both for SCSI and for
CD-ROM-like hardware, e.g. CD-ROM and DVD devices, ZIP
drives, tape drives, SCSI pass-through, etc.)
uaehf.device uses IOCTL functionality (see
below), and does not require SPTI or ASPI. It provides limited
emulation of SCSI commands, e.g. for HDToolBox and similar system tools, for mounting devices and for booting from them,
and to support file systems and partitions, in a way similar to
the boot ROMs that are included with Amiga SCSI controllers.
uaescsi.device uses either SPTI (Windows 2000, Windows XP and
higher) or ASPI functionality (Windows 98 and Windows Me),
depending on the version of Windows and the installed software (see
Because the emulation needs to merge and support units from
different access interfaces, SCSI ID (unit) numbers inside the
Amiga environment have no relationship with "real" device ID or
unit numbers. In particular, uaescsi.device
unit numbers 0 and 1 are reserved (and automatically remapped, if
necessary) to the first two CD-ROM/DVD type devices.
Additionally, a "uae.device" may be used
for mounted directories. This is generally
not referenced in any applications, since it
provides no useful functionality.
Other Amiga SCSI Devices
With the Amiga 3000, Commodore introduced a real SCSI disk system and "scsi.device"
support file. When the Amiga 4000 was released (with IDE only, no SCSI),
Commodore opted to keep the "scsi.device" name for the support file, and modify
the functionality, to allow booting from IDE media and keep using the same
tools (such as HDToolBox) that already had "scsi.device" in their ToolTypes and
other settings. Also, the IDE variant of Commodore's scsi.device included
limited SCSI emulation, which was enough for some programs to work (in a way
similar to uaehf.device), and to extend the capacity of IDE support to about 8
GB (if the file system had direct SCSI support, such as SPS and SFS) at times
when a 4 GB limit was common. This can be confusing because Commodore had two
different device files, both named "scsi.device", but one being a full SCSI
implementation, and the other an IDE variant.
Amiga Forever SCSI & IDE Settings (Windows Side)
If you determine that you need to use uaescsi.device, make sure that the
SCSI & IDE option is selected in the Amiga Forever configuration (right-click the
title, select Edit, then check SCSI & IDE in the Devices group of the Configuration
As a general rule, in order to avoid accidental access and
corruption of non-Amiga data, the emulation will only mount
disks that are recognized as either being empty or having Amiga-formatted
content. This means that by default it is not possible to mount PC-formatted
disks, or disks formatted under custom Amiga partition schemes, such as those
developed before the release of the Amiga Rigid Disk Block specification, or
Amiga SCSI Settings (Amiga Side)
All Amiga programs that support SCSI peripherals have one ore
more configuration parameters (ToolType, command line option,
etc.) that need to be set to the proper device name and unit
number. So be sure to set the correct device name
("uaehf.device" or "uaescsi.device") and unit number.
Within the Workbench 3.X environment of Amiga Forever you can
use the "FindDevice" tool (in "Work:Software/IDEfix97") to
verify that a device has been recognized, and to obtain the unit
number as it has been mapped within the emulation environment.
The WinUAE log file, if enabled, also lists the unit numbers
that have been assigned to recognized devices.
Windows IOCTL Support
The virtual uaehf.device device which is part of the Amiga emulation uses the
Windows IOCTL (I/O Control Code) software interface to provide
access to devices. IOCTL is supported on Windows 2000, Windows
XP, Windows Server 2003, Windows Vista, Windows 7 and later
versions of Windows. It only supports block-type devices
like hard disks, including USB storage media, flash memory
As a rule of thumb, if Windows detects such a device and
allows you to configure it in Disk Management (found under
Storage, in Computer Management), WinUAE can use it via
This functionality requires administrator privileges.
Windows SPTI and ASPI Support
The virtual uaescsi.device device which is part of the Amiga emulation uses
either the Windows SPTI (SCSI Pass Through Interface) or the
Windows ASPI (Advanced SCSI Programming
Interface) software interface to provide access to devices. ASPI is included by Microsoft in
Windows 95, Windows 98, and Windows Me. ASPI is not directly
supported by Microsoft on Windows NT and newer versions of
Windows, where it has been replaced by the newer SPTI. In order to maintain compatibility with
different versions of Windows the Amiga emulation software can
use either SPTI or ASPI.
While it should not be required on newer versions of Windows (since they
include SPTI), it is possible to install a third-party ASPI
component. This software is made available (often for free
download, or as part of evaluation versions of their software)
by companies like
Adaptec. If you have a recordable CD or DVD writer mounted in your
system then you most likely already have such software
installed. It has been reported that the software by
is more compatible than the one by
Adaptec when used with CD-like devices and hard drives.
Apparently however the Nero software may not support certain
other devices, such as scanners.
In WinUAE 1.0 and higher, the ASPI software is
detected automatically. In previous versions of WinUAE you may
need to copy the ASPI DLL file (e.g. "wnaspi.dll") to the WinUAE
program directory. SPTI is supported by WinUAE 1.1.1 and
Limited Functionality on Older Versions of Windows
The procedures described here are fully supported only on Windows 10,
Windows 8, Windows 7, Windows Vista, Windows XP (with SP3) and equivalent
Windows Server editions,
using WinUAE 1.1.1 and higher.
Support for Windows 2000 is limited in some cases, reflecting
system API limitations. SCSI and the other low-level device
access interfaces and procedures described here are not supported in WinFellow.
Under Windows 2000 WinUAE has limited access to the exact
hard disk configuration. In particular, it can only get generic
information about the hard drive geometry, which is usually not
enough to calculate the total disk size up to the exact end of
the disk. This means that when reading Amiga disk partitions
formatted using the FFS or OFS file systems some errors may
occur when reading or writing the last few blocks. Similarly,
partitions formatted using the SFS file system cannot be mounted
at all, because SFS places crucial information in the last block
of a partition.
Beginning with version 0.9.92 WinUAE started supporting the
new IOCTL_DISK_GET_LENGTH_INFO functionality first introduced in
Windows XP, and also available in newer versions of Windows, which makes it possible to
obtain the exact disk size, overcoming the above limitations.
Additional Notes on Disk Images
We have seen cases of Amiga partitions where the high and low bytes were swapped (e.g. the
"RDSK" header had become "DRKS"). This can be corrected with a
good hex editor, after which the partitions can be mounted
within the Amiga emulation.