FAQ

This page addresses typical questions on HDDRIVER and also provides general information on mass storage devices and the Atari.

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 more than four partitions created by very old versions of the ICD driver software, which was using a non-standard partition 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.
When installing HDDRIVER another already installed hard disk driver will automatically be disabled.

How do I perform an update?

An update is performed in the same way as the installation: Update HDDRIVER by double-clicking drive C: in the HDDRUTIL drive window. During an update, the settings of an already existing driver file HDDRIVER.SYS are automatically re-used. The original HDDRIVER.SYS file is renamed to HDDRIVER.OLD.

Why does HDDRIVER only detect four partitions even though there are more?

Quite likely the drive was partitioned with a not fully AHDI compatible software, e.g. with a very old version of the ICD software. HDDRIVER includes software that without losing data converts the ICD format to the AHDI format, which is the standard for Ataris.

What is the maximum drive/memory card capacity supported by HDDRIVER?

On any interface HDDRIVER supports devices and memory cards with a capacity of up to 1 EiB (Exbibyte). Drives > 2 TiB cannot be used by TOS, MagiC or MiNT with their full capacity, though, because these systems only support 32 bit sector numbers. Tools like HDDRUTIL or DISKUS, which support 64 bit sector numbers, can access sectors beyond the 2 TiB limit by using the SCSI Driver integrated in HDDRIVER. In order to use the full capacity of media > 1 GiB with the ACSI bus, a suitable host adapter (ICD compatible), suitable card readers (GigaFile or UltraSatan) or emulations like SCSI2Pi are required.

What is the maximum partition size supported by HDDRIVER?

For each version of TOS HDDRIVER supports the respective maximum partition size. TOS 1.00-1.02 supports partitions of up to 256 MiB, TOS 1.04-3.06 of up to 512 MiB, TOS 4.0x of up to 1 GiB. These sizes are also valid for boot partitions and TOS/Windows compatible partitions. With MagiC, the non-boot partition size can be up to 1 GiB. When partitioning with maximum size, you should stay right under the respective limits, i.e. 255.9 MiB, 511.9 MiB or 1023.9 MiB. MiNT and MagiC support filesystems (FAT32/ext2) with partition sizes up to 2 TiB. Note that these values are based on 1024 bytes per KiB, not on 1000 bytes per KB. In HDDRUTIL you can configure the preferred unit.
When the partition size is > 1 GiB, HDDRUTIL automatically creates a FAT32 instead of a FAT16 partition when partitioning. HDDRUTIL displays the maximum FAT16 partition size supported by the current operating system with "System Limits".

How many drives/partitions does HDDRIVER support?

With TOS HDDRIVER supports 16 drives (A:-P:), because partitions can also be assigned to the drives A: and B:. With MagiC, MiNT or Big-DOS HDDRIVER supports 31 drives (A:-Z: except U: and 1: to 6:).
HDDRUTIL displays the maximum number of drives supported by the current operating system with "System Limits".

Is it possible to boot from GPT partitions?

Yes, HDDRIVER can be installed on GPT partitions, and you can boot from them without restrictions.

Does HDDRIVER support the GPT partition scheme, which is the standard on PCs and Macs?

Yes, HDDRIVER and HDDRUTIL support both the MBR and the modern GPT scheme.

Do drives/memory cards have to be formatted before partitioning?

No, formatting is only required for drives/memory cards with bad sectors. In all other cases it is a waste of time. Modern SATA drives do not support formatting anymore.

How can I store data on DVD-RAM, DVD+RW or BD-RE media with HDDRIVER?

In order to use these media with a regular TOS filesystem "Manage Multimedia Drives" in the "Removable Media/Memory Cards" settings has to be enabled. With this option HDDRIVER also manages multimedia drives, and you can partition them and use them for storing data.

Does HDDRIVER belong into the AUTO folder?

Usually not, because HDDRUTIL installs HDDRIVER as HDDRIVER.SYS in the root directory of the boot partition selected during the driver installation.
Only software emulators, where the system is not booted from a drive image but from a emulated GEMDOS drive, require HDDRIVER.PRG in the AUTO folder of this drive.

Does HDDRIVER require AUTO folder programs like FOLDRxxx, CACHExxx, JARxxx or SCSIDRV?

No, with HDDRIVER these programs are not needed because their functionality is already built-in. HDDRIVER can be configured with the respective settings instead.

Can accessories be loaded from a different drive than C:?

Yes, because TOS automatically loads accessories from the boot drive when there are no ACCs on drive C:. If there are any ACCs on drive C:, though, they are always loaded from there. This is a feature of TOS, not of HDDRIVER.
HDDRIVER supports several ways of selecting the boot drive.

Hardware Support

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 a customary adapter that reduces the bus width to 8 bit.

Which hardware supports drives/memory cards > 1 GiB with 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.

What has to be considered with the UltraSatan?

Using firmware version 1.30 or newer is required. Also note that the UltraSatan ignores the write protection switch setting.
Just like for any device with removable media, for the UltraSatan the settings for removable media, which can be configured with HDDRUTIL, are relevant.

What has to be considered with the GigaFile?

GigaFile revisions older than R08 cannot access the last sector of an SD card if the GigaFile is connected to the SCSI bus. Thus HDDRUTIL reports an error when partitioning. There is no issue with the ACSI bus.
Just like for any device with removable media, for the GigaFile the settings for removable media, 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 primary or secondary drive.

Are there any limitations when booting from ACSI?

With drives connected to the ACSI bus the boot partition has to be located within the first Gigabyte of a drive. Furthermore, on a TT TOS can only boot from the ACSI bus when HDDRIVER is not loaded into TT-RAM.

Are there any limitations when booting from IDE?

TOS can only boot from a drive connected as primary 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 as other platforms. The Suska board uses the normal IDE byte order and is not affected by this limitation.
With IDE/SATA drives the boot partition has to be located within the first 32 Gigabytes of a drive. Further, TOS cannot boot from 4KN SATA drives, which have 4096 physical bytes per sector.

Which addresses do the 4 Atari IDE ports supported by HDDRIVER have?

The addresses of the first three ports are $FFF00000, $FFF00040 and $FFF00080. The address of port 4 with the ST/STE is $FFF000C0. With the MegaSTE and TT it is $00BFFB00 and $FEDFFB00, resp., because these addresses are used by the VME version of the ATW800/2 transputer card. With the Falcon it is $FEF00000, because this address is used by the CTPCI board. HDDRIVER supports 2 devices (primary and secondary) per port.

Does HDDRIVER support USB drives?

HDDRIVER and HDDRUTIL support any interface for which a SCSI Driver is available, and therefore also USB drives. Developers of new interfaces just need to provide a SCSI Driver for their hardware, in the ideal case as an HDDRIVER module. See the SCSI Driver page for a list of available SCSI Drivers.
HDDRIVER itself provides integrated SCSI Drivers for Atari ACSI, Atari SCSI and Atari/Milan IDE/ATAPI/SATA.

Data Exchange

Does HDDRIVER support exchanging data with PCs and Macs?

Yes, data can easily be exchanged without any additional software with Windows, macOS, Linux and BSD. Both FAT16 and FAT32 partitions (the latter only with MagiC or MiNT) can be used for the data exchange. HDDRUTIL and HDDRIVER support partitioning in MBR and in the modern GPT format, which is the standard on PCs and Macs.

Why does Windows find only one partition on a removable medium even though there are several?

This is a limitation of old Windows versions. Only Windows 10 and newer support more than one partition on removable media drives. This also applies to memory cards).

Why can TOS partitions > 256 MiB 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.

Can TOS boot HDDRIVER from a TOS/Windows compatible medium?

Yes, provided that the medium is not byteswapped. TOS/Windows compatible media used with the Atari's IDE interface have to be byteswapped, i. e. TOS cannot boot from them. One can boot, though, from TOS/Windows compatible media used with the ACSI or SCSI bus.
Therefore, for instance, with UltraSatan, GigaFile, SCSI2Pi or BlueSCSI HDDRIVER can be booted from TOS/Windows compatible memory cards.

Does byteswapping affect single partitions or the whole medium?

Byteswapping always affects the whole medium, i.e. all partitions on the medium. HDDRIVER supports automatic byte-swapping for any bus without special hardware.

Other

Which SCSI level should be configured with devices that support several levels?

You should always configure the latest level, e.g. SCSI-2 instead of SCSI-1. This also applies to devices connected to the ACSI port. HDDRIVER and HDDRUTIL automatically use commands newer than SCSI-2 for optimizations.

Does the internal host adapter of the MegaSTE support more than one device?

Yes, with SCSI2Pi and BlueSCSI up to 8 emulated devices are possible also with the MegaSTE. When it is about physical devices only a single device is supported.

Are Atari computers restricted to only use certain SCSI commands?

No, there are no restrictions for TT, Falcon and for STs with an ICD compatible host adapter. Any SCSI command can be used, not just those defined in the SCSI-2 specification. With a real SCSI bus or ICD-compatible ACSI host adapters, HDDRIVER, HDDRUTIL and the SCSI Driver Test Tool also use commands from newer standards than SCSI-2, if available.

What do SCSI "initiator identification" and "bus arbitration" mean?

Initiator identification means that a computer uses its own unique SCSI ID when communicating with a device. Without initiator identification some devices do not work properly or do not even respond. Bus arbitration depends on initiator IDs and ensures a proper SCSI bus handling when there is more than one computer (initiator) on the same bus.
With TT and Falcon SCSI initiator identification and bus arbitration is controlled by software and HDDRIVER supports it. With ACSI bus arbitration is not possible, but the LINK96/97 and the host adapter by Inventronik provide initiator identification by hardware.

What is wrong when 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 is unique. 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.
The SCSI ID setting only has an effect when a driver like HDDRIVER with SCSI initiator ID support is used. TT, Falcon and Milan store their SCSI ID in the NVRAM.

Are the transfer rates of memory cards higher than those of IDE/SATA hard drives?

Not necessarily. Most memory cards do not support the IDE transfer mode READ/WRITE MULTIPLE. Only some Industrial Grade cards offer this mode. IDE hard drives usually provide higher transfer rates than memory cards, even though they have longer access times. These differences are easily measurable with Atari computers.

Is there anything to consider with Cubase Audio?

Cubase Audio does not handle the Falcon's SCSI bus in compliance with the SCSI standard, which can lead to issues. The only workaround is using the last version 7.93 of the HDDRIVER 7 series. This version lacks numerous features, requires more memory, is less performant, potentially does not support modern hardware, 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, but should verify first whether with their hardware there are actually issues with the current HDDRIVER and Cubase.

Does HDDRIVER use the _hz_200 system variable?

Not with SCSI and IDE. With ACSI it depends on the performance settings. In the accelerated ACSI mode _hz_200 is not used. Timer C is always required, though, in order to detect timeouts.

Can I use HDDRUTIL with a different driver than HDDRIVER?

Yes, because many functions of HDDRUTIL only require SCSI Driver or XHDI support. Any driver that provides a correct implementation of these software interfaces is fine for running HDDRUTIL. This is the case for any type of hardware interface, e.g. also for USB.