trackdisk.library Reference

Comprehensive function reference for trackdisk.library, synthesised from the AmigaOS NDK 3.2 Release 4 (Autodocs/AG/trackdisk).

This page documents 19 functions of trackdisk.library. Each function entry follows the canonical autodoc format. struct Name, union Name, enum Name are clickable links to the type definition in the types reference.

Function index

CMD_CLEAR()

CMD_CLEAR/ETD_CLEAR -- mark the track buffer as containing invalid data.

Function

These commands mark the track buffer as invalid, forcing a reread of the disk on the next operation. ETD_UPDATE or CMD_UPDATE would be used to force data out to the disk before turning the motor off. ETD_CLEAR or CMD_CLEAR are usually used after having locked out the trackdisk.device via the use of the disk resource, when you wish to prevent the track from being updated, or when you wish to force the track to be re-read. ETD_CLEAR or CMD_CLEAR will not do an update, nor will an update command do a clear.

IO REQUEST INPUT io_Device preset by the call to OpenDevice() io_Unit preset by the call to OpenDevice() io_Command CMD_CLEAR or ETD_CLEAR io_Flags 0 or IOF_QUICK iotd_Count (ETD_CLEAR only) maximum allowable change counter value.

IO REQUEST RESULT io_Error - 0 for success, or an error code as defined in

CMD_READ()

CMD_READ/ETD_READ -- read sectors of data from a disk.

Function

These commands transfer data from the track buffer to a supplied buffer. If the desired sector is already in the track buffer, no disk activity is initiated. If the desired sector is not in the buffer, the track containing that sector is automatically read in. If the data in the current track buffer has been modified, it is written out to the disk before a new track is read. ETD_READ will read the sector label area if the iotd_SecLabel is non-NULL.

IO REQUEST INPUT io_Device preset by the call to OpenDevice() io_Unit preset by the call to OpenDevice() io_Command CMD_READ or ETD_READ io_Flags 0 or IOF_QUICK io_Data pointer to the buffer where the data should be put io_Length number of bytes to read, must be a multiple of TD_SECTOR. io_Offset byte offset from the start of the disk describing where to read data from, must be a multiple of TD_SECTOR. iotd_Count (ETD_READ only) maximum allowable change counter value. iotd_SecLabel (ETD_READ only) NULL or sector label buffer pointer. If provided, the buffer must be a multiple of TD_LABELSIZE.

IO REQUEST RESULT io_Error - 0 for success, or an error code as defined in

Notes

Under versions of Kickstart earlier than V36, the io_Data had to point to a buffer in chip memory. This restriction is no longer present as of Kickstart V36 and beyond.

CMD_UPDATE()

CMD_UPDATE/ETD_UPDATE -- write out the track buffer if it is dirty.

Function

The trackdisk device does not write data sectors unless it is necessary (you request that a different track be used) or until the user requests that an update be performed. This improves system speed by caching disk operations. These commands ensure that any buffered data is flushed out to the disk. If the track buffer has not been changed since the track was read in, these commands do nothing. ETD_UPDATE command checks for diskchange.

IO REQUEST INPUT io_Device preset by the call to OpenDevice() io_Unit preset by the call to OpenDevice() io_Command CMD_UPDATE or ETD_UPDATE io_Flags 0 or IOF_QUICK iotd_Count (ETD_UPDATE only) maximum allowable change counter value.

IO REQUEST RESULT io_Error - 0 for success, or an error code as defined in

CMD_WRITE()

CMD_WRITE/ETD_WRITE -- write sectors of data to a disk.

Function

These commands transfer data from a supplied buffer to the track buffer. If the track that contains this sector is already in the track buffer, no disk activity is initiated. If the desired sector is not in the buffer, the track containing that sector is automatically read in. If the data in the current track buffer has been modified, it is written out to the disk before the new track is read in for modification. ETD_WRITE will write the sector label area if iotd_SecLabel is non-NULL.

IO REQUEST INPUT io_Device preset by the call to OpenDevice() io_Unit preset by the call to OpenDevice() io_Command CMD_WRITE or ETD_WRITE io_Flags 0 or IOF_QUICK io_Data pointer to the buffer where the data should be put io_Length number of bytes to write, must be a multiple of TD_SECTOR. io_Offset byte offset from the start of the disk describing where to write data to, must be a multiple of TD_SECTOR. iotd_Count (ETD_WRITE only) maximum allowable change counter value. iotd_SecLabel (ETD_WRITE only) NULL or sector label buffer pointer. If provided, the buffer must be a multiple of TD_LABELSIZE.

IO REQUEST RESULT io_Error - 0 for success, or an error code as defined in

Notes

Under versions of Kickstart earlier than V36, the io_Data had to point to a buffer in chip memory. This restriction is no longer present as of Kickstart V36 and beyond.

OpenDevice()

OpenDevice -- open a trackdisk unit

Synopsis

OpenDevice( devName, iORequest, UnitNumber, Flags ), DevNode A0 A1 D0 D1 A6

Function

Grands access to a specific unit of the trackdisk.device

Inputs

iORequest -- an I/O Request Block that the Open routine should initialize.

UnitNumber -- a number between 0 and 3, identifying the
drives 0 to 3.

Flags -- TDF_ALLOW_NON_3_5: If this flag is set,
    then the trackdisk.device also opens 5.25" devices
    otherwise, such drives remain invisible.

Results

0 for success, or an error code from

Bugs

If the unit was already opened anytime before the Flags are ignored and OpenDevice always succeeds.

TD_ADDCHANGEINT()

TD_ADDCHANGEINT -- add a disk change software interrupt handler.

Function

This command lets you add a software interrupt handler to the disk device that gets invoked whenever a disk insertion or removal occurs.

You must pass in a properly initialized Exec Interrupt structure
and be prepared to deal with disk insertions/removals
immediately. From within the interrupt handler, you may only call the
status commands that can use IOF_QUICK.

To set up the handler, an Interrupt structure must be initialized.
This structure is supplied as the io_Data to the TD_ADDCHANGEINT
command. The handler then gets linked into the handler chain and
gets invoked whenever a disk change happens. You must eventually
remove the handler before you exit.

This command only returns when the handler is removed. That is,
the device holds onto the IO request until the TD_REMCHANGEINT command
is executed with that same IO request. Hence, you must use SendIO()
with this command.

IO REQUEST INPUT io_Device preset by the call to OpenDevice() io_Unit preset by the call to OpenDevice() io_Command TD_ADDCHANGEINT io_Flags 0 io_Length sizeof(struct Interrupt) io_Data pointer to Interrupt structure

IO REQUEST RESULT io_Error - 0 for success, or an error code as defined in

Bugs

As this command is issued with SendIO(), the issuer will not be notified when exactly the change interrupt becomes active, and in particular, when TD_REMCHANGEINT can be issued to remove the interrupt again. If TD_ADDCHANGEINT and TD_REMCHANGEINT are send shortly after each other without a task switch taking place, the TD_REMCHANGEINT could have caused bad side effects in V45 and before. While the trackdisk.device became aware of this race condition in V47, it is still advisable to perform any other command via DoIO(), e.g. TD_MOTOR, to ensure that the interrupt is really queued in, and is safe to remove.

See also

Cause()

TD_CHANGENUM()

TD_CHANGENUM -- return the current value of the disk-change counter.

Function

This command returns the current value of the disk-change counter (as used by the enhanced commands). The disk change counter is incremented each time a disk is inserted or removed from the trackdisk unit.

IO REQUEST INPUT io_Device preset by the call to OpenDevice() io_Unit preset by the call to OpenDevice() io_Command TD_CHANGENUM io_Flags 0 or IOF_QUICK

IO REQUEST RESULT io_Error - 0 for success, or an error code as defined in io_Actual - if io_Error is 0, this contains the current value of the disk-change counter.

TD_CHANGESTATE()

TD_CHANGESTATE -- check if a disk is currently in a drive.

Function

This command checks to see if there is currently a disk in a drive.

IO REQUEST INPUT io_Device preset by the call to OpenDevice() io_Unit preset by the call to OpenDevice() io_Command TD_CHANGESTATE io_Flags 0 or IOF_QUICK

IO REQUEST RESULT io_Error - 0 for success, or an error code as defined in io_Actual - if io_Error is 0, this tells you whether a disk is in the drive. 0 means there is a disk, while anything else indicates there is no disk.

TD_EJECT()

TD_EJECT -- eject (or load) the disk in the drive, if possible.

Function

This command causes the drive to attempt to eject the disk in it, if any. Note that the current trackdisk.device does not implement this command, but it might in the future, and other trackdisk-compatible drivers may implement this command. Some devices may be able to load disks on command also.

IO REQUEST INPUT io_Device preset by the call to OpenDevice() io_Unit preset by the call to OpenDevice() io_Command TD_EJECT io_Flags 0 or IOF_QUICK io_Length 0 (load, if supported) or 1 (eject)

IO REQUEST RESULT io_Error - 0 for success, or an error code as defined in

Bugs

The pre-V40 autodoc didn't mention io_Length. Because of this, for devices that can never support load, a driver might want to eject if io_Length is 0.

TD_FORMAT()

TD_FORMAT/ETD_FORMAT -- format a track on a disk.

Function

These commands are used to write data to a track that either has not yet been formatted or has had a hard error on a standard write command. TD_FORMAT completely ignores all data currently on a track and does not check for disk change before performing the command. The io_Data field must point to at least one track worth of data. The io_Offset field must be track aligned, and the io_Length field must be in units of track length (that is, NUMSEC*TD_SECTOR).

The device will format the requested tracks, filling each sector with
the contents of the buffer pointed to by io_Data. You
should do a read pass to verify the data.

If you have a hard write error during a normal write, you may find it
possible to use the TD_FORMAT command to reformat the track as part of
your error recovery process. ETD_FORMAT will write the sector label
area if iotd_SecLabel is non-NULL.

IO REQUEST INPUT io_Device preset by the call to OpenDevice() io_Unit preset by the call to OpenDevice() io_Command TD_FORMAT or ETD_FORMAT io_Flags 0 or IOF_QUICK io_Data points to a buffer containing the data to write to the track, must be at least as large as io_Length. io_Length number of bytes to format, must be a multiple of (TD_SECTORS * NUMSEC). io_Offset byte offset from the start of the disk for the track to format, must be a multiple of (TD_SECTORS * NUMSEC). iotd_Count (ETD_FORMAT only) maximum allowable change counter value. iotd_SecLabel (ETD_FORMAT only) NULL or sector label buffer pointer. If provided, the buffer must be a multiple of (TD_LABELSIZE * NUMSEC).

IO REQUEST RESULT io_Error - 0 for success, or an error code as defined in

Notes

Under versions of Kickstart earlier than V36, the io_Data had to point to a buffer in chip memory. This restriction is no longer present as of Kickstart V36 and beyond.

TD_GETDRIVETYPE()

TD_GETDRIVETYPE -- return the type of disk drive for the unit that was opened.

Function

This command returns the type of the disk drive to the user. This number will be a small integer and will come from the set of DRIVEXXX constants defined in .

The only way you can actually use this command is if the trackdisk
device understands the drive type of the hardware that is plugged in.
This is because the OpenDevice() call will fail if the trackdisk device
does not understand the drive type. To find raw drive identifiers see
the disk.resource's DR_GETUNITID entry point.

IO REQUEST INPUT io_Device preset by the call to OpenDevice() io_Unit preset by the call to OpenDevice() io_Command TD_GETDRIVETYPE io_Flags 0 or IOF_QUICK

IO REQUEST RESULT io_Error - 0 for success, or an error code as defined in io_Actual - if io_Error is 0 this contains the drive type connected to this unit.

TD_GETGEOMETRY()

TD_GETGEOMETRY -- return the geometry of the drive.

Function

This command returns a full set of information about the layout of the drive. The information is returned in the DriveGeometry structure pointed to by io_Data.

IO REQUEST INPUT io_Device preset by the call to OpenDevice() io_Unit preset by the call to OpenDevice() io_Command TD_GETGEOMETRY io_Flags 0 or IOF_QUICK io_Data Pointer to a DriveGeometry structure io_Length sizeof(struct DriveGeometry)

IO REQUEST RESULT io_Error - 0 for success, or an error code as defined in

Note

This information may change when a disk is inserted when certain hardware is present.

TD_GETNUMTRACKS()

TD_GETNUMTRACKS -- return the number of tracks for the type of disk drive for the unit that was opened.

Function

This command returns the number of tracks that are available on the disk unit.

IO REQUEST INPUT io_Device preset by the call to OpenDevice() io_Unit preset by the call to OpenDevice() io_Command TD_GETNUMTRACKS io_Flags 0 or IOF_QUICK

IO REQUEST RESULT io_Error - 0 for success, or an error code as defined in io_Actual - if io_Error is 0 this contains the number of tracks accessible on this unit

TD_MOTOR()

TD_MOTOR/ETD_MOTOR -- control the on/off state of a drive motor.

Function

This command gives control over the disk motor. The motor may be turned on or off. When it is on, the drive light automatically turns on as well.

If the motor is just being turned on, the device will delay the
proper amount of time to allow the drive to come up to speed. Normally,
turning the drive on is not necessary, the device does this
automatically if it receives a request when the motor is off. However,
turning the motor off is the programmer's responsibility.

In addition, the standard instructions to the user are that it is safe
to remove a disk from a drive if and only if the motor is off (that is,
if the disk light is off).

IO REQUEST INPUT io_Device preset by the call to OpenDevice() io_Unit preset by the call to OpenDevice() io_Command TD_MOTOR or ETD_MOTOR io_Flags 0 or IOF_QUICK io_Length the requested state of the motor, 0 to turn the motor off, and 1 to turn the motor on. iotd_Count (ETD_MOTOR only) maximum allowable change counter value.

IO REQUEST RESULT io_Error - 0 for success, or an error code as defined in io_Actual - if io_Error is 0 this contains the previous state of the drive motor.

TD_PROTSTATUS()

TD_PROTSTATUS -- return whether the current disk is write-protected.

Function

This command is used to determine whether the current disk is write-protected.

IO REQUEST INPUT io_Device preset by the call to OpenDevice() io_Unit preset by the call to OpenDevice() io_Command TD_PROTSTATUS io_Flags 0 or IOF_QUICK

IO REQUEST RESULT io_Error - 0 for success, or an error code as defined in io_Actual - if io_Error is 0, this tells you whether the disk in the drive is write-protected. 0 means the disk is NOT write- protected, while any other value indicates it is.

TD_RAWREAD()

TD_RAWREAD/ETD_RAWREAD -- read raw data from the disk.

Function

These commands read a track of raw data from disk and deposits it in the provided buffer. The data is taken straight from the disk with no processing done on it. It will appear exactly as the bits come out off the disk, hopefully in some legal MFM format.

This interface is intended for sophisticated programmers only.
Commodore-Amiga reserves the right to make enhancements to the disk
format in the future. We will provide compatibility via the
CMD_READ and ETD_READ commands, anyone using TD_RAWREAD is
bypassing this upwards compatibility, and may thus stop working.

IO REQUEST INPUT io_Device preset by the call to OpenDevice() io_Unit preset by the call to OpenDevice() io_Command TD_RAWREAD or ETD_RAWREAD. io_Flags If the IOTDB_INDEXSYNC bit is set then the driver will make a best effort attempt to start reading from the index mark. Note that there will be at least some delay, and perhaps a great deal of delay (for example if interrupts have been disabled). If the IOTDB_WORDSYNC bit is set it will use the WORDSYNC ability to sync on $4489. Sorry, you cannot specify the sync pattern. You may set both INDEXSYNC and WORDSYNC, in which case it will do index sync first, then start a wordsync read. io_Length Length of buffer in bytes, with a maximum of 32766 bytes. io_Data Pointer to CHIP memory buffer where raw track data is to be deposited. io_Offset The number of the track to read in. iotd_Count (ETD_RAWREAD only) maximum allowable change counter value.

IO REQUEST RESULT io_Error - 0 for success, or an error code as defined in

Notes

The track buffer provided MUST be in CHIP memory

There is a delay between the index pulse and the start of bits
coming in from the drive (e.g. dma started). This delay
is in the range of 135-200 microseconds. This delay breaks
down as follows: 55 microsecs is software interrupt overhead
(this is the time from interrupt to the write of the DSKLEN
register). 66 microsecs is one horizontal line delay (remember
that disk IO is synchronized with agnus' display fetches).
The last variable (0-65 microsecs) is an additional scan line
since DSKLEN is poked anywhere in the horizontal line. This leaves
15 microsecs unaccounted for...  Sigh.

In short, You will almost never get bits within the first 135
microseconds of the index pulse, and may not get it until 200
microseconds. At 4 microsecs/bit, this works out to be between
4 and 7 bytes of user data of delay.

Bugs

This command does not work reliably under versions of Kickstart earlier than V36, especially on systems with 1 floppy drive.

TD_RAWWRITE()

TD_RAWWRITE/ETD_RAWWRITE -- write raw data to the disk.

Function

This command writes a track of raw data from the provided buffer to the specified track on disk. The data is copied straight to the disk with no processing done on it. It will appear exactly on the disk as it is in the memory buffer, hopefully in a legal MFM format.

This interface is intended for sophisticated programmers only.
Commodore-Amiga reserves the right to make enhancements to the disk
format in the future. We will provide compatibility via the
CMD_WRITE and ETD_WRITE commands, anyone using TD_RAWWRITE is
bypassing this upwards compatibility, and may thus stop working.

IO REQUEST INPUT io_Device preset by the call to OpenDevice() io_Unit preset by the call to OpenDevice() io_Command TD_RAWWRITE or ETD_RAWWRITE. io_Flags If the IOTDB_INDEXSYNC bit is set then the driver will make a best effort attempt to start writing from the index mark. Note that there will be at least some delay, and perhaps a great deal of delay (for example if interrupts have been disabled). If the IOTDB_WORDSYNC bit is set it will use the WORDSYNC ability to sync on $4489. Sorry, you cannot specify the sync pattern. You may set both INDEXSYNC and WORDSYNC, in which case it will do index sync first, then start a wordsync write. io_Length Length of buffer in bytes, with a maximum of 32766 bytes. io_Data Pointer to CHIP memory buffer where raw track data is to be taken. io_Offset The number of the track to write to. iotd_Count (ETD_RAWWRITE only) maximum allowable change counter value.

IO REQUEST RESULT io_Error - 0 for success, or an error code as defined in

Notes

The track buffer provided MUST be in CHIP memory

There is a delay between the index pulse and the start of bits
going out to the driver (e.g. write gate enabled). This delay
is in the range of 135-200 microseconds. This delay breaks
down as follows: 55 microsecs is software interrupt overhead
(this is the time from interrupt to the write of the DSKLEN
register). 66 microsecs is one horizontal line delay (remember
that disk IO is synchronized with agnus' display fetches).
The last variable (0-65 microsecs) is an additional scan line
since DSKLEN is poked anywhere in the horizontal line. This leaves
15 microsecs unaccounted for...  Sigh.

In short, You will almost never get bits within the first 135
microseconds of the index pulse, and may not get it until 200
microseconds. At 4 microsecs/bit, this works out to be between
4 and 7 bytes of user data of delay.

Bugs

This command does not work reliably under versions of Kickstart earlier than V36, especially on systems with 1 floppy drive.

TD_REMCHANGEINT()

TD_REMCHANGEINT -- remove a disk change software interrupt handler.

Function

This command removes a disk change software interrupt added by a previous use of TD_ADDCHANGEINT.

IO REQUEST INPUT The same IO request used for TD_ADDCHANGEINT.

io_Device   preset by the call to OpenDevice()
io_Unit     preset by the call to OpenDevice()
io_Command  TD_REMCHANGEINT
io_Flags    0
io_Length   sizeof(struct Interrupt)
io_Data     pointer to Interrupt structure

IO REQUEST RESULT io_Error - 0 for success, or an error code as defined in

Bugs

This command did not function properly under versions of Kickstart earlier than V36. A valid workaround under these older versions of Kickstart is:

    Forbid();
    Remove(ioRequest);
    Permit();

Do not use this workaround in versions of Kickstart >= V36, use
TD_REMCHANGEINT instead (for future compatibility with V38+).

This command did not function properly under versions of Kickstart
earlier than V47 either in case a TD_ADDCHANGEINT was issued
to the device, but not yet processed. This got fixed in V47.

TD_SEEK()

TD_SEEK/ETD_SEEK -- control positioning of the drive heads.

Function

These commands are currently provided for internal diagnostics, disk repair, and head cleaning only.

TD_SEEK and ETD_SEEK move the drive heads to the track specified. The
io_Offset field should be set to the (byte) offset to which the seek is
to occur. TD_SEEK and ETD_SEEK do not verify their position until the
next read. That is, they only move the heads; they do not actually read
any data.

IO REQUEST INPUT io_Device preset by the call to OpenDevice() io_Unit preset by the call to OpenDevice() io_Command TD_SEEK or ETD_SEEK io_Flags 0 or IOF_QUICK io_Offset byte offset from the start of the disk describing where to move the head to. iotd_Count (ETD_SEEK only) maximum allowable change counter value.

IO REQUEST RESULT io_Error - 0 for success, or an error code as defined in