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irwin(HW)

irwin, mc -- Irwin tape drive interface

Description

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'' device. 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:


1xx
5¼ inch drive (mounted in system cabinet)

2xx
3½ inch drive (mounted in system cabinet)

3xx
5¼ inch drive in a metal cabinet with power supply

4xx
3½ inch drive in a plastic cabinet (no supply)

7xx
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).


xx0
250 kilobits/second

xx5
500 kilobits/second

xx7
1 megabit/second
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.


2020
3½ inch, 20 megabyte, 250 kilobits/second

2040
3½ inch, 40 megabyte, 500 kilobits/second

2080
3½ inch, 80/120 megabyte, 500 kilobits/second

2120
3½ inch, 80/120 megabyte, 1 megabit/second

Mini cartridges

There are three primary physical mini-cartridges types:


DC1000
185 feet of 0.150 inch wide tape (same as TC-200)

DC2000
205 feet of 0.250 inch wide tape (same as TC-400)

DC2120
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 cartridge formats:

Mini (Irwin) cartridge format parameters

  AccuTrak       Sectors/      
  reorder   Total   Blocks per Cartridge
number   tape Trks per block Density format
(see Notes) Cartridge blocks   track Data ECC (FTPI)  
110 1000-10 DC1000 1264 8 158 8 0 6400
120 2000-20 DC2000 1190 14 85 16 2 6400
120XL 2000-30 DC2120 1792 14 128 16 2 6400
125 1000-20 DC1000 1320 12 110 16 2 10000
145 2000-40 DC2000 2480 20 124 16 2 10000
145XL 2000-60 DC2120 3720 20 186 16 2 10000
165 2000-64 DC2000 3936 24 164 16 2 13200
285 2000-80 DC2000 2752 32 86 29 3 11600
285XL 2000-120 DC2120 4160 32 130 29 3 11600 

 +----------+-------------+-----------+--------+------+----------+------+-----+---------+
 |          | AccuTrak    |           |        |      | Sectors/ |      |     |         |
 +----------+-------------+-----------+--------+------+----------+------+-----+---------+
 |          | reorder     |           | Total  |      | Blocks   | per        |         |
 +----------+-------------+-----------+--------+------+----------+------------+---------+
 |Cartridge | number      |           | tape   | Trks | per      | block      | Density |
 +----------+-------------+-----------+--------+------+----------+------+-----+---------+
 |format    | (see Notes) | Cartridge | blocks |      | track    | Data | ECC | (FTPI)  |
 +----------+-------------+-----------+--------+------+----------+------+-----+---------+
 |110       | 1000-10     | DC1000    | 1264   | 8    | 158      | 8    | 0   | 6400    |
 +----------+-------------+-----------+--------+------+----------+------+-----+---------+
 |120       | 2000-20     | DC2000    | 1190   | 14   | 85       | 16   | 2   | 6400    |
 +----------+-------------+-----------+--------+------+----------+------+-----+---------+
 |120XL     | 2000-30     | DC2120    | 1792   | 14   | 128      | 16   | 2   | 6400    |
 +----------+-------------+-----------+--------+------+----------+------+-----+---------+
 |125       | 1000-20     | DC1000    | 1320   | 12   | 110      | 16   | 2   | 10000   |
 +----------+-------------+-----------+--------+------+----------+------+-----+---------+
 |145       | 2000-40     | DC2000    | 2480   | 20   | 124      | 16   | 2   | 10000   |
 +----------+-------------+-----------+--------+------+----------+------+-----+---------+
 |145XL     | 2000-60     | DC2120    | 3720   | 20   | 186      | 16   | 2   | 10000   |
 +----------+-------------+-----------+--------+------+----------+------+-----+---------+
 |165       | 2000-64     | DC2000    | 3936   | 24   | 164      | 16   | 2   | 13200   |
 +----------+-------------+-----------+--------+------+----------+------+-----+---------+
 |285       | 2000-80     | DC2000    | 2752   | 32   | 86       | 29   | 3   | 11600   |
 +----------+-------------+-----------+--------+------+----------+------+-----+---------+
 |285XL     | 2000-120    | DC2120    | 4160   | 32   | 130      | 29   | 3   | 11600   |
 +----------+-------------+-----------+--------+------+----------+------+-----+---------+

Notes:
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 model
    2020   2040        
    720 725 745        
    420 425 445 765 2080 2120  
  410 320 325 345 465 785 787  
Cartridge 310 220 225 245 265 485 487  
format 110 120 125 145 165 285 287 Cartridge
110 rw rw r- r- r- r- r- DC1000
120 -- rw -- r- r- r- r- DC2000
120XL -- rw -- r- r- r- r- DC2120
125 -- -- rw rw r- r- r- DC1000
145 -- -- -- rw r- r- r- DC2000
145XL -- -- -- rw r- r- r- DC2120
165 -- -- -- -- rw r- r- DC2000
285 -- -- -- -- -- rw rw DC2000
285XL -- -- -- -- -- rw rw DC2120 

 +----------+-----+---------------------------------------------------+
 |          |     | Drive model                                       |
 +----------+-----+------+-----+------+-----+------+------+-----------+
 |          |     | 2020 |     | 2040 |     |      |      |           |
 +----------+-----+------+-----+------+-----+------+------+-----------+
 |          |     | 720  | 725 | 745  |     |      |      |           |
 +----------+-----+------+-----+------+-----+------+------+-----------+
 |          |     | 420  | 425 | 445  | 765 | 2080 | 2120 |           |
 +----------+-----+------+-----+------+-----+------+------+-----------+
 |          | 410 | 320  | 325 | 345  | 465 | 785  | 787  |           |
 +----------+-----+------+-----+------+-----+------+------+-----------+
 |Cartridge | 310 | 220  | 225 | 245  | 265 | 485  | 487  |           |
 +----------+-----+------+-----+------+-----+------+------+-----------+
 |format    | 110 | 120  | 125 | 145  | 165 | 285  | 287  | Cartridge |
 +----------+-----+------+-----+------+-----+------+------+-----------+
 |110       | rw  | rw   | r-  | r-   | r-  | r-   | r-   | DC1000    |
 +----------+-----+------+-----+------+-----+------+------+-----------+
 |120       | --  | rw   | --  | r-   | r-  | r-   | r-   | DC2000    |
 +----------+-----+------+-----+------+-----+------+------+-----------+
 |120XL     | --  | rw   | --  | r-   | r-  | r-   | r-   | DC2120    |
 +----------+-----+------+-----+------+-----+------+------+-----------+
 |125       | --  | --   | rw  | rw   | r-  | r-   | r-   | DC1000    |
 +----------+-----+------+-----+------+-----+------+------+-----------+
 |145       | --  | --   | --  | rw   | r-  | r-   | r-   | DC2000    |
 +----------+-----+------+-----+------+-----+------+------+-----------+
 |145XL     | --  | --   | --  | rw   | r-  | r-   | r-   | DC2120    |
 +----------+-----+------+-----+------+-----+------+------+-----------+
 |165       | --  | --   | --  | --   | rw  | r-   | r-   | DC2000    |
 +----------+-----+------+-----+------+-----+------+------+-----------+
 |285       | --  | --   | --  | --   | --  | rw   | rw   | DC2000    |
 +----------+-----+------+-----+------+-----+------+------+-----------+
 |285XL     | --  | --   | --  | --   | --  | rw   | rw   | DC2120    |
 +----------+-----+------+-----+------+-----+------+------+-----------+
Key:

r
Drive reads cartridge format

w
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 cartridge:

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:

120, 220, 320, 420, 720, 2020, 145, 245, 345, 445, 745, 2040

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 mcart(C) utility. If the command mcart drive reports a drive type with the suffix XL, formatting of DC2120 cartridges is supported.

Diagnostics

The following error messages may be displayed on the console. See messages(M) 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: 
Close
Control error
Daemon start
Read
Write
ir_msg gives more information about the error. This may be one of: 
Bad block address
Bad count
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
DMA overrun
Daemon not started
Data CRC error
Defect list corrupt
Defect list has unrecoverable error
Device busy
Device busy formatting
Device performing diagnostic
Drive not found
Drive not ready
Equipment fault
Erase failure
Error on sense interrupt status
Error sending command to drive
Error starting data transfer
Floppy controller reset failure
ID CRC error
Incompatible cartridge
Insufficient memory
Internal error
Invalid parameter
Maximum block relocation tries reached
Medium changed
Memory address conversion error
No ID address mark
No data address mark
No error
No servo
Operating system call failed
Read after write miscompare
Record not found
Request aborted
Request timed out
Seek track error
Sense drive status failure
Servo but no sector format
Servo failure
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
Unexpected interrupt
Unrecognized controller error
Unsupported drive command
Vector installation failure
Write protected

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.

Limitations

It is recommend that you only use preformatted-formatted Irwin tapes. Otherwise, Irwin tapes must be servo-written and then formatted with tape(C) before use; this can take a substantial amount of time.

Files


/dev/rctmini
default tape device; linked to /dev/rmc0

/dev/rmc0
raw interface device file

/dev/xmc0
control interface device file

See also

mcart(C), mcconfig(F), mkdev(ADM), tape(C), tape(HW)
© 2003 Caldera International, Inc. All rights reserved.
SCO OpenServer Release 5.0.7 -- 11 February 2003