diff options
Diffstat (limited to 'usr.bin/mt/mt.1')
| -rw-r--r-- | usr.bin/mt/mt.1 | 149 |
1 files changed, 97 insertions, 52 deletions
diff --git a/usr.bin/mt/mt.1 b/usr.bin/mt/mt.1 index 8c6fab8..d8a66d3 100644 --- a/usr.bin/mt/mt.1 +++ b/usr.bin/mt/mt.1 @@ -87,8 +87,8 @@ Rewind the tape Rewind the tape and place the tape unit off-line (Count is ignored). .It Cm erase -Erase the tape -(Count is ignored). +Erase the tape. +A count of 0 disables long erase, which is on by default. .It Cm retension Re-tension the tape (one full wind forth and back, Count is ignored). @@ -115,8 +115,35 @@ Forward space to end of data, identical to .Cm eom . .It Cm comp Set compression mode. -(The kernel counterpart of this has not yet been reported to work -correctly.) +There are currently several possible values for the compression mode: +.Pp +.Bl -tag -width 123456789 -compact +.It off +Turn compression off +.It on +Turn compression on +.It none +Same as +.Ar off +.It enable +Same as +.Ar on +.It IDRC +IBM Improved Data Recording Capability compression (0x10). +.It DCLZ +DCLZ compression algorithm (0x20). +.El +.Pp +In addition to the above recognized compression keywords, the user can +supply a numeric compression algorithm for the tape drive to use. In most +cases, simply turning the compression +.Sq on +will have the desired effect of enabling the default compression algorithm +supported by the drive. If this is not the case (see the +.Cm status +display to see which compression algorithm is currently in use), the user +can manually specify one of the supported compression keywords (above), or +supply a numeric compression value. .El .Pp If a tape name is not specified, and the environment variable @@ -124,66 +151,84 @@ If a tape name is not specified, and the environment variable does not exist; .Nm uses the device -.Pa /dev/nrst0 . +.Pa /dev/nrsa0 . .Pp .Nm Mt returns a 0 exit status when the operation(s) were successful, 1 if the command was unrecognized, and 2 if an operation failed. .Pp +The following density table was taken from the +.Sq Historical sequential access density codes +table (A-1) in Revision 11 of the SCSI-3 Stream Device Commands (SSC) +working draft, dated November 11, 1997. +.Pp The different density codes are as follows: .Pp .Dl 0x0 default for device .Dl 0xE reserved for ECMA -.Bd -literal -offset indent -Value Tracks Density(bpi) Code Type Reference Note -0x1 9 800 NRZI R X3.22-1983 2 -0x2 9 1600 PE R X3.39-1986 2 -0x3 9 6250 GCR R X3.54-1986 2 -0x5 4/9 8000 GCR C X3.136-1986 1 -0x6 9 3200 PE R X3.157-1987 2 -0x7 4 6400 IMFM C X3.116-1986 1 -0x8 4 8000 GCR CS X3.158-1986 1 -0x9 18 37871 GCR C X3B5/87-099 2 -0xA 22 6667 MFM C X3B5/86-199 1 -0xB 4 1600 PE C X3.56-1986 1 -0xC 24 12690 GCR C HI-TC1 1,5 -0xD 24 25380 GCR C HI-TC2 1,5 -0xF 15 10000 GCR C QIC-120 1,5 -0x10 18 10000 GCR C QIC-150 1,5 -0x11 26 16000 GCR C QIC-320(525?) 1,5 -0x12 30 51667 RLL C QIC-1350 1,5 -0x13 1 61000 DDS CS X3B5/88-185A 4 -0x14 1 43245 RLL CS X3.202-1991 4 -0x15 1 45434 RLL CS ECMA TC17 4 -0x16 48 10000 MFM C X3.193-1990 1 -0x17 48 42500 MFM C X3B5/91-174 1 -.Ed - -where Code means: -.Bd -literal -offset indent -NRZI Non Return to Zero, change on ones -GCR Group Code Recording -PE Phase Encoded -IMFM Inverted Modified Frequency Modulation -MFM Modified Frequency Modulation -DDS Dat Data Storage -RLL Run Length Encoding +.Bd -literal -offset 3n +Value Width Tracks Density Code Type Reference Note + mm in bpmm bpi +0x01 12.7 (0.5) 9 32 (800) NRZI R X3.22-1983 2 +0x02 12.7 (0.5) 9 63 (1,600) PE R X3.39-1986 2 +0x03 12.7 (0.5) 9 246 (6,250) GCR R X3.54-1986 2 +0x05 6.3 (0.25) 4/9 315 (8,000) GCR C X3.136-1986 1 +0x06 12.7 (0.5) 9 126 (3,200) PE R X3.157-1987 2 +0x07 6.3 (0.25) 4 252 (6,400) IMFM C X3.116-1986 1 +0x08 3.81 (0.15) 4 315 (8,000) GCR CS X3.158-1987 1 +0x09 12.7 (0.5) 18 1,491 (37,871) GCR C X3.180 2 +0x0A 12.7 (0.5) 22 262 (6,667) MFM C X3B5/86-199 1 +0x0B 6.3 (0.25) 4 63 (1,600) PE C X3.56-1986 1 +0x0C 12.7 (0.5) 24 500 (12,690) GCR C HI-TC1 1,6 +0x0D 12.7 (0.5) 24 999 (25,380) GCR C HI-TC2 1,6 +0x0F 6.3 (0.25) 15 394 (10,000) GCR C QIC-120 1,6 +0x10 6.3 (0.25) 18 394 (10,000) GCR C QIC-150 1,6 +0x11 6.3 (0.25) 26 630 (16,000) GCR C QIC-320 1,6 +0x12 6.3 (0.25) 30 2,034 (51,667) RLL C QIC-1350 1,6 +0x13 3.81 (0.15) 1 2,400 (61,000) DDS CS X3B5/88-185A 5 +0x14 8.0 (0.315) 1 1,703 (43,245) RLL CS X3.202-1991 5 +0x15 8.0 (0.315) 1 1,789 (45,434) RLL CS ECMA TC17 5 +0x16 12.7 (0.5) 48 394 (10,000) MFM C X3.193-1990 1 +0x17 12.7 (0.5) 48 1,673 (42,500) MFM C X3B5/91-174 1 +0x18 12.7 (0.5) 112 1,673 (42,500) MFM C X3B5/92-50 1 +0x1C 6.3 (0.25) 34 1,654 (42,000) MFM C QIC-385M 1,6 +0x1D 6.3 (0.25) 32 1,512 (38,400) GCR C QIC-410M 1,6 +0x1E 6.3 (0.25) 30 1,385 (36,000) GCR C QIC-1000C 1,6 +0x1F 6.3 (0.25) 30 2,666 (67,733) RLL C QIC-2100C 1,6 +0x20 6.3 (0.25) 144 2,666 (67,733) RLL C QIC-6GB(M) 1,6 +0x21 6.3 (0.25) 144 2,666 (67,733) RLL C QIC-20GB(C) 1,6 +0x22 6.3 (0.25) 42 1,600 (40,640) GCR C QIC-2GB(C) ? +0x23 6.3 (0.25) 38 2,666 (67,733) RLL C QIC-875M ? +0x24 3.81 (0.15) 1 2,400 (61,000) CS DDS-2 5 +0x25 3.81 (0.15) 1 3,816 (97,000) CS DDS-3 5 +0x26 3.81 (0.15) 1 3,816 (97,000) CS DDS-4 5 +0x27 8.0 (0.315) 1 3,056 (77,611) RLL CS Mammoth 5 +0x28 12.7 (0.5) 36 1,491 (37,871) GCR C X3.224 1 +0x29 12.7 (0.5) +0x2A +0x2B 12.7 (0.5) 3 ? ? ? C X3.267 5 .Ed -where Type means: -.Bd -literal -offset indent -R Reel-to-Reel -C Cartridge -CS cassette +.Bd -literal -offset 3n +Code Description Type Description +---------------- ---------------- +NRZI Non return to zero, change on ones R Reel-to-reel +GCR Group code recording C Cartridge +PE Phase encoded CS Cassette +IMFM Inverted modified frequency modulation +MFM Modified frequency modulation +DDS DAT data storage +RLL Run length limited .Ed -where Notes means: -.Bd -literal -offset indent -1 Serial Recorded -2 Parallel Recorded -3 Old format know as QIC-11 -4 Helical Scan -5 Not ANSI standard, rather industry standard. +.Bd -literal -offset 3n +NOTES +1. Serial recorded. +2. Parallel recorded. +3. Old format known as QIC-11. +5. Helical scan. +6. This is not an American National Standard. The reference is based on + an industry standard definition of the media format. .Ed .Sh ENVIRONMENT @@ -202,7 +247,7 @@ is not given. .Bl -tag -width /dev/*rst[0-9]*xx -compact .It Pa /dev/*rwt* QIC-02/QIC-36 magnetic tape interface -.It Pa /dev/*rst[0-9]* +.It Pa /dev/*rsa[0-9]* SCSI magnetic tape interface .El .Sh SEE ALSO |
