Retro1.org codex

FORMAT                                                    CMS User Area command

Use the FORMAT command to:
o   Initialize a virtual disk (minidisk) for use with CMS files.
o   Count or reset the number of cylinders on a virtual disk.
o   Write a label on a virtual disk.
The format of the FORMAT command is:
+----------+------------------------------------------------------------------+
| FORMAT   | cuu mode [numcyl] [( [Label] [Recomp] [)]]                       |
+----------+------------------------------------------------------------------+
where:

cuu      is the virtual device address of the virtual disk to be formatted.

         Valid addresses are 001 through 5FF for a virtual machine in basic
         control mode and 001 through FFF for a virtual machine in extended
         control mode.

mode     is the filemode letter to be assigned to the specified device address.
         Valid filemode letters are A through G, Y, and Z.  This field must be
         specified. If any other disk is accessed at this mode, it is released.

numcyl   is the number of cylinders to be made available for use.  All
         available cylinders on the disk are used if the number specified
         exceeds the actual number available.

Options:

Label    writes a label on the disk without formatting the disk.  The CMS disk
         label is written on cylinder 0, track 0, record 3 of the virtual disk.
         A prompting message requests a six-character disk label (fewer than
         six characters are left-justified and blanks padded).

Recomp   changes the number of cylinders on the disk that are available to the
         user to the actual number of minidisk cylinders or to the number
         specified by numcyl, whichever is less.  If numcyl is not specified
         all cylinders are used.


Usage notes:

1.  You can use the FORMAT command with any virtual 3330, 3340, 3350, 3380, or
    2314 device.

2.  When you do not specify either the RECOMP or LABEL option, the disk area is
    initialized by writing a device-dependent number of records (containing
    binary zeros) on each track.  Any previous data on the disk is erased.  A
    read after write check is made as the disk is formatted.  For example:
       format 191 a  25
    initializes 25 cylinders of the disk located at virtual address 191 in CMS
    format.  The command:
       format 192 b  25 (recomp)
    changes the number of cylinders available at virtual address 192 to 25
    cylinders, but does not erase any existing CMS files.  To change only the
    label on a disk, you can enter:
       format 193 c (label)
    Respond to the prompting message with a six-character label.

3.  If you want to format a minidisk for VSAM files, you must use the IBCDASDI
    program.  If you want to format an entire disk, you may use any OS or DOS
    disk initialization program.

4.  While you can only specify filemode letters of A through G, Y, and Z with
    the FORMAT command, you can use the ACCESS command to access a virtual disk
    at any letter, A through Z.

Responses:

DMSFOR603R     FORMAT WILL ERASE ALL FILES ON DISK 'mode(cuu)'.  DO YOU WISH TO
               CONTINUE? (YES¦NO):
    You have indicated that a disk area is to be initialized; all existing
    files are erased.  This message gives you the option of canceling the
    execution of the FORMAT command.  Reply yes or no.

DMSFOR605R    ENTER DISK LABEL:
    You have requested that a label be written on the disk.  Enter a 1- to 6-
    character label.

DMSFOR705I    DISK REMAINS UNCHANGED
    The response to message DMSFOR603R was 'NO', or a null line was entered.

DMSFOR732I    'nnn' CYLINDERS FORMATTED ON DISK 'mode(cuu)'
    The format operation is complete.

DMSFOR733I    FORMATTING DISK 'mode'
    The disk represented by mode letter 'mode' is being formatted.

mode (cuu): nnnn FILEs, nnnnn REC IN USE, nnnnn LEFT (of nnnnn), nn% FULL (nnn
            CYL), type, R/W
    This message provides the status of a disk when you use the RECOMP option.