Planning Considerations for I I I 2314/ I I 2319 3330 3340 I 3350
rI , , Maximum number of files , 3500 3400 3400 , 3400 I that can be contained on , I , the disk I I .. I I I Maximum minidisk size I 203 246 348 , 115 , (in cylinders) I (model 35) , 1 , 682 , I , (model 70) , .. +-- I I Number of 800-byte blocks I 150 266 96 I 570 , per cylinder I I .. I , Maximum data extent records ""'-',-'...Iv , 12,848,000 bytes
L
Figure 3.CMS Disk File Statistics
IDENTIFYINGDISK FILES CMS commands are provided to list the identifications of files on eMS and non-CMS formatted disks and minidisks. The LISTFILE command. lists
the entries in the master file directory forCMS disks; the LISTDS command lists the entries in the VTOC (volume table of contents) for as
andDOS disks, or for listing data spaces on VSAM volumes. eMS Tape Support
EachCMS machine can support up to four magnetic tape units at virtual
addresses 181, 182, 183, and 184. They may be 2401, 2402, 2403, 2415,
2420, 3410/3411, or 3420 drives, or a mixture of tape drives.
Three tape-handling commands(ASSGN, FILEDEF, and TAPE) allow you to
specify the modeset of the tape: track (7-track or 9-track), density,
and, for 7-track tape only, the tape recording technique (odd or even
parity, converter on or off, and translator on or off)• If you do not specify the modeset for a 7-track tape, CMS issues a
modeset indicating 7-track,800 bpi (bits per inch), odd parity,
converter on, and translate off. If the tape is 9-track, the density is
assumed to be1600 bpi (or whatever bpi the tape drive was last set at)
for dual density drives; for single density drives, whatever bpi the
drive is(800, 1600, or 6250 bpi) is assumed.
As an alternative to specifying mode in each command that uses the
tape (for example, FILEDEF), you can issue aCMS TAPE command that sets
the mode for the tape and stays in effect until reissued.You must do
this if one of your programs is to use tapes in other than the default
mode.With one exception, eMS commands permit only unlabeled tapes to be
read or written. However, theeMS TAPPDS command can read standard as
tape labels.Your programs executing under eMS must use unlabeled tapes
or provide code to create and read their own labels as data records.Part 1. Planning for System Generation 27
r
L
Figure 3.
IDENTIFYING
the entries in the master file directory for
and
Each
addresses 181, 182, 183, and 184. They may be 2401, 2402, 2403, 2415,
2420, 3410/3411, or 3420 drives, or a mixture of tape drives.
Three tape-handling commands
specify the modeset of the tape: track (7-track or 9-track), density,
and, for 7-track tape only, the tape recording technique (odd or even
parity, converter on or off, and translator on or off)
modeset indicating 7-track,
converter on, and translate off. If the tape is 9-track, the density is
assumed to be
for dual density drives; for single density drives, whatever bpi the
drive is
As an alternative to specifying mode in each command that uses the
tape (for example, FILEDEF), you can issue a
the mode for the tape and stays in effect until reissued.
this if one of your programs is to use tapes in other than the default
mode.
read or written. However, the
tape labels.
or provide code to create and read their own labels as data records.