This page addresses some frequent questions and provides tips related to storage devices connected to the Atari. Note that some of this information applies to the current version of HDDRIVER only.

Installation and Partitioning
Do I lose any data when switching to HDDRIVER from another driver?
No, all existing data remain unchanged when installing HDDRIVER. Drives with partitions created by old versions of the ICD driver software, which was using a non-standard partitioning scheme, require a special treament. In this case data have to be converted with software that is included in the HDDRIVER distribution. No data are lost by this conversion.
How much RAM does HDDRIVER need?
The amount of memory required by hard disk drivers for the Atari depends on the size of the biggest partition to be managed. Configured for minimum memory usage and with small partitions HDDRIVER allocates less than 28 KiB RAM.
HDDRUTIL requires 1 MiB of RAM.
What is the maximum drive capacity supported by HDDRIVER?
HDDRIVER supports drives of any capacity. Drives > 2 TiB cannot be used by TOS, MagiC or MiNT with their full capacity. Tools like HDDRUTIL and DISKUS, which support 64 bit sector numbers, can access sectors beyond the 2 TiB limit by using the SCSI Driver integrated in HDDRIVER. With the ACSI bus of the ST/STE mass storage devices with a capacity > 1 GiB can only be used with their full capacity with suitable host adapters or suitable memory card adapters.
What is the maximum partition size supported by HDDRIVER?
The maximum partition size in the first place depends on the operating system and on the filesystem. TOS 1.00/1.02 support partitions of up to 256 MiB, TOS 1.04-3.06 of up to 512 MiB, TOS 4.0x of up to 1 GiB, MagiC of up to 2 GiB. These sizes are also valid for boot partitions and TOS/Windows compatible partitions. With Big-DOS the TOS limits can be lifted. MiNT and MagiC support filesystems (FAT32/ext2) that do not have any relevant size limit.
How many drives/partitions does HDDRIVER support?
All TOS versions support up to 16 BIOS drives (A:-P:). With HDDRIVER all of these drives can be assigned to partitions. With MagiC HDDRIVER supports up to 25 partitions (A:-Z: except U:), with MiNT or Big-DOS up to 31 partitions (A:-Z: except U: and 1:-6:).
Do individual partitions have to be initialized after partitioning?
No, this is not recommended. Initializing a partition is a potentially dangerous operation, which requires expert knowledge and only makes sense in special cases.
Does HDDRIVER belong into the AUTO folder?
No, HDDRUTIL always installs HDDRIVER as HDDRIVER.SYS in the root directory of the partition selected during the driver installation. It does not make sense to additionally place HDDRIVER in the AUTO folder.
There is only one exception: Special installations in software emulators, where the system is not booted from an emulated hard disk drive but from a GEMDOS drive, require HDDRIVER.PRG in the AUTO folder of this drive.
Does HDDRIVER require additional AUTO folder programs like FOLDRxxx or CACHExxx?
No, with HDDRIVER these programs are not needed. HDDRIVER can be configured with the respective settings instead.
Hardware Support
Does HDDRIVER support memory cards?
Yes, memory cards like SD, CF or MMC are fully supported by HDDRIVER. They are ideal for exchanging data with other platforms, and they are inexpensive and noiseless alternatives to hard disk drives. HDDRIVER can boot from a memory card.
Note that for memory cards the HDDRIVER settings for removable media are relevant.
Does HDDRIVER support Atari SH and Megafile drives?
Yes, all drives of the SH and Megafile series are fully supported.
Does HDDRIVER support any SCSI drive?
Any Single Ended SCSI drive (but no LVD SCSI drives) can be used with the TT's or Falcon's SCSI bus. Drives with a bus width of 16 bit (e.g drives with an SCA connector) require an adapter that reduces the bus width to 8 bit. These adapters are offered by numerous vendors.
Which hardware supports drives/memory cards > 1 GiB connected to the ACSI bus?
SCSI drives > 1 GiB connected to the ACSI bus require special hardware in order to make use of the full drive capacity. Suitable hardware are the adapters by Inventronik, the GigaFile, the UltraSatan, the ICD Link and the LINK96/97. (This list may not be complete.)
HDDRIVER does not detect a SCSI drive connected to the ST/STE.
ST and STE do not have a real SCSI bus but only Atari's proprietary ACSI bus. Certain devices (those that require the so-called initiator identification) connected to this bus can only be used with the LINK96/97 host adapters or the adapters by Inventronik. Additionally, when using other adapters it may be required to switch off the drive's parity checking.
Does HDDRIVER support SATA drives?
Yes, with a standard IDE-to-SATA adapter SATA hard disk drives/SSDs or SATA DVD/BD drives can be connected to the IDE port and can be used with HDDRIVER.
Does HDDRIVER support IDE or SATA drives connected to the SCSI bus?
Yes, with an Acard AEC-7720U SCSI-to-IDE bridge IDE and SATA (with an additional IDE-to-SATA adapter) drives have been successfully used with the SCSI bus and HDDRIVER. How well this works may vary depending on the particular drive and adapter, though.
Does HDDRIVER support the UltraSatan?
Yes, but due to incompatibilities with the SCSI standard in old UltraSatan firmwares using firmware version 1.20 or newer is required.
Just like for any device with removable media, for the UltraSatan the settings for removable media drives, which can be configured with HDDRUTIL, are relevant.
Each time when booting HDDRIVER reports a different ID for an IDE/ATAPI/SATA drive.
IDE and ATAPI devices connected to the Atari should not be operated in the Cable Select mode, but should be explicitly jumpered either as master or slave drive.
Are there any limitations when booting from ACSI?
TOS can only boot from the ACSI bus when the hard disk driver being booted is not loaded into the Alternate RAM (TT-RAM).
Are there any limitations when booting from IDE?
TOS can only boot from a drive connected as master drive to the first IDE port if the drive was partitioned while being connected to the Atari's IDE port. This is caused by the wiring of the Atari's IDE port not having the same byte order used by other platforms for IDE.
The Suska board uses the same byte order as other platforms and does not have this limitation.
Is HDDRIVER prepared for new hardware interfaces?
Yes, it is. Even though HDDRIVER itself will most likely not support interfaces not fully compatible with the interfaces of the ST, TT or Falcon030, provisions have been made: HDDRIVER and HDDRUTIL support any hardware interface for which a SCSI Driver is available. Developers of new interfaces just need to provide a SCSI Driver for their hardware. See the downloads page for a list of available SCSI Drivers.
HDDRIVER itself includes SCSI drivers for Atari ACSI, Atari SCSI, Atari/Milan IDE, Atari/Milan ATAPI and Atari/Milan SATA.
Data Exchange
Does HDDRIVER support exchanging data with PCs and Macs?
Yes, with the help of the TOS/Windows-compatible partitioning data can easily be exchanged without any additional software with Windows (Windows XP and newer), Linux and macOS. Both FAT16 and FAT32 partitions (the latter only with MagiC or MiNT) can be used for the data exchange.
TOS/Windows compatible media do not work with Windows or macOS.
The media may have been created with the wrong physical drive parameters or with the wrong byte order. Manually adjusting these parameters when partitioning may help.
Why does Windows only find one partition on a removable medium even though there are several?
This is a basic limitation of Windows: On drives Windows considers removable (this also applies to memory cards) only a single partition is supported. With Windows several partitions per drive are only possible with fixed disk drives.
Why can big TOS partitions not be mounted under Linux?
The maximum logical sector size supported by Linux is 4096 bytes. TOS partitions compatible with TOS 1.00/1.02 and bigger than 128 MiB, and TOS partitions compatible with TOS 1.04 or newer and bigger than 256 MiB have logical sectors bigger than 4096 bytes. Under Linux these partitions can only be used with mtools. TOS/Windows compatible partitions of the same size have smaller logical sectors and can be mounted as Windows partitions.
Can TOS boot HDDRIVER from a TOS/Windows compatible partition?
Yes, provided the partition is not byte-swapped. TOS/Windows compatible media used with the IDE bus of an Atari have to be byte-swapped, i. e. TOS cannot boot from them. One can boot, though, from TOS/Windows compatible media used with the ACSI or SCSI bus, because no byte-swapping is required for these buses.
Therefore in particular with UltraSatan or GigaFile HDDRIVER can be booted from TOS/Windows compatible memory cards.
Are the transfer rates of memory cards always higher than those of hard disk drives?
No, because memory cards usually do not support the IDE transfer mode READ/WRITE MULTIPLE. Thus IDE hard disk drives often offer higher transfer rates than memory cards, even though they have longer access times. These differences are clearly measurable with the Atari.
What is wrong if the same SCSI device is reported for all SCSI IDs?
This happens when the computer's SCSI ID is identical with the SCSI ID of one of the connected devices. Ensure that the SCSI ID of your TT or Falcon, which is stored in the NVRAM, is unique. Additionally, the computer's SCSI ID should be the highest SCSI ID on the bus, i.e. 7 if only one computer is connected to the bus.
Is there anything to consider when using Cubase Audio?
Cubase Audio does not handle the Falcon's SCSI bus compliant to the standard, which can lead to problems with HDDRIVER 8 and newer. If the CAFFIX software, which is included in the HDDRIVER distribution, cannot put things right and because there are no versions of Cubase where this problem has been fixed, the only work-around is using the last version 7.93 of the HDDRIVER 7 series. This version does not support as many peripherals as current versions of HDDRIVER but is known to work with Cubase. Most functions of the current HDDRUTIL can also be used with HDDRIVER 7.93, by the way.
Users of newer versions of HDDRIVER can request HDDRIVER 7.93 for free by e-mail.
Does HDDRIVER support Hatari?
Yes, but Hatari's SCSI emulation is incomplete. With Hatari you should configure HDDRIVER to not check for any SCSI devices, otherwise starting HDDRIVER takes very long. With ACSI drive images Hatari 1.8.0 or newer should be used because the ACSI emulation in older versions is quite buggy.
By the way, with Hatari you can use the emulated IDE drives also with TOS 2.06 and 3.06, but in contrast to TOS 2.06 and 4.0x, TOS 3.06 cannot boot from IDE drives.
Can I use HDDRUTIL with a different driver than HDDRIVER?
Yes, the maintainance functions of HDDRUTIL only require SCSI Driver and XHDI support. Any driver that provides a correct implementation of these open and non-proprietary software interfaces is fine for running HDDRUTIL. This is the case for any type of hardware interface, also for potentially new interfaces of Atari clones.