A single Irwin tape drive connected to the
floppy disk controller is supported by the
mc device driver.
ECC encoding and decoding is automatically used with
the standard raw device /dev/rmc0; there is no ``no-rewind''
On the Irwin 80MB drive,
3KB of ECC data is written
for every 29KB of ordinary data written to the tape
to provide error recovery.
On the Irwin 10, 20, 40 and 60MB drives,
2KB of ECC data is written for every 16KB of ordinary data
written to the tape.
You may find that the mc driver can read tapes
formatted and written under old versions of the operating system
but that it cannot write to them.
Irwin drive models
Many Irwin mini-cartridge drives have a three-digit model number.
The high-order digit encodes the form factor and cabinetry:
5¼ inch drive (mounted in system cabinet)
3½ inch drive (mounted in system cabinet)
5¼ inch drive in a metal cabinet with power supply
3½ inch drive in a plastic cabinet (no supply)
3½ inch drive in a metal cabinet with power supply
The middle digit gives the approximate capacity, in 10MB
units, for a standard capacity (not extra-long) tape.
The low digit encodes the drive's normal data transfer rate (that
is, the floppy controller data clock rate).
In addition, a new 4-digit model numbering system is in use. These
model numbers are associated with drives which are adaptable to
different system hardware environments with accessory hardware kits.
3½ inch, 20 megabyte, 250 kilobits/second
3½ inch, 40 megabyte, 500 kilobits/second
3½ inch, 80/120 megabyte, 500 kilobits/second
3½ inch, 80/120 megabyte, 1 megabit/second
There are three primary physical mini-cartridges types:
185 feet of 0.150 inch wide tape (same as TC-200)
205 feet of 0.250 inch wide tape (same as TC-400)
307.5 feet of 0.250 inch wide tape
The DC1000 cartridge is physically thinner than
DC2000 and DC2120 cartridges.
The DC2000 and DC2120 have the same physical form but
the DC2120 has a longer tape. These cartridges are distinguished
by their labels. Each physical cartridge type has at least two
Mini (Irwin) cartridge format parameters
The suffix part of the AccuTrak reorder number is an
approximate cartridge capacity in megabytes.
All formats use 1024-byte MFM encoded sectors.
Drive read/write compatibility for mini-cartridge formats
Drive reads cartridge format
Drive writes cartridge format
Incompatible: When a cartridge is formatted but incompatible for
reading or writing, the driver reports that the cartridge is either
incompatible or erased.
Extra long (XL) DC2120 cartridge compatibility
Extra long (that is, DC2120) cartridges are incompatible with the
following drives; the drive will not physically accommodate the
110, 310, 410, 125, 225, 325, 425, and 725
Even though DC2120 cartridges are physically accepted in the
following drives, you may not be able to format them:
Drives manufactured prior to 1989 don't recognize the
longer tape. However, the mc driver is able to read and write
preformatted extra long tapes in these drives, but it is unable to
correctly format them. Formatting will start, but terminate in
error. To determine whether a drive supports formatting of DC2120
cartridges, use the
If the command mcart drive
reports a drive type with the suffix XL,
formatting of DC2120 cartridges is supported.
The following error messages may be displayed on the console.
for general information about kernel error messages,
including a list of generic device driver errors.
NOTICE: ir: type error m on tape unit n dev major/minor: ir_msg
type is the status of the tape drive when the error occurred. This
may be one of:
ir_msg gives more information about the error. This may
be one of:
Bad block address
Bad device number
Bad operation code
Block 0 corrupt
Block 0 medium error
Block 0 missing servo header
Block allocation failure
Block merge failure
Block not found
Block relocation failure
Controller not found
Cylinder not found
DMA attempt past end of cylinder
DMA boundary error
Daemon not started
Data CRC error
Defect list corrupt
Defect list has unrecoverable error
Device busy formatting
Device performing diagnostic
Drive not found
Drive not ready
Error on sense interrupt status
Error sending command to drive
Error starting data transfer
Floppy controller reset failure
ID CRC error
Maximum block relocation tries reached
Memory address conversion error
No ID address mark
No data address mark
Operating system call failed
Read after write miscompare
Record not found
Request timed out
Seek track error
Sense drive status failure
Servo but no sector format
State machine hung
Timeout reading controller result
Timeout writing controller command
Timer initialization failure
Too many bad blocks
Too many bad blocks on a track
Too many missing servo headers
Too many missing servo headers on track
Too many outstanding interrupts
Too many sequential bad blocks
Too many sequential missing servo headers
Track following error
Unrecognized controller error
Unsupported drive command
Vector installation failure
WARNING: ir: Attempt to write past end of tape unit n dev major/minor
The end of the tape has been reached unexpectedly.
WARNING: ir: Bad tape header
The tape header is unreadable.
WARNING: ir: Cannot write old tape format
The drive is not capable of writing in an old tape format.
WARNING: ir: Fatal error during format
Formatting of the tape failed.
WARNING: ir: ir_format - not enough memory
Not enough memory could be allocated to format the tape.
WARNING: ir: irfm0 - Tape is write-protected
Move the write protect slider on the cartridge to the RECORD position.
Also check for damage to the drive and the tape cartridge.
WARNING: ir: irwrite - Drive type (dt) does not match tape type (tt)
Possible drive and tape types are IR_10, IR_20,
IR_25, IR_45, IR_46, IR_65, and
IR_85. The driver reports incompatible drive and tape types.
It is recommend that you only use preformatted-formatted Irwin tapes.
Otherwise, Irwin tapes must be servo-written and
then formatted with
before use; this can take a substantial amount of time.