SECTION III

DISC DIRECTORY COMMANDS


The Disc Directory is a table of all library programs and files, giving the
name, disc location and last date referenced for each.  The Disc Directory
resides on the disc.  One track of directory space is reserved per disc de-
fined logically in the system (these tracks might all reside on the same
disc).  The location and length of the disc directory tracks is given by the
STATUS Command.  (See Section V).


DIRECTORY


The DIRECTORY Command is initiated by the word

                          DIRECTORY

This causes the system to print a list of library programs and
files according to user IDcode.  For every program of file the
following information is listed:

  NAME        the program name (1 to 6 characters)

  DATE        last date this program was referenced (day of
              year/last two digits of year)

  DISC ADR.   location of program on disc (disc number/track/
              sector) in decimal.

  LENGTH      length of program in decimal words.







Example of a DIRECTORY Command Output

       DIRECTORY
         ID   NAME    DATE    DISC ADR   LENGTH
        A000  ABOUT   100/69  0/23/037   0090
              F3      072/69  0/23/035   0087
              FORGET  100/69  0/23/033   0090
              HELLO   100/69  0/23/032   0027
              PROGN   072/69  0/23/030   0101
              RFET    070/69  0/23/028   0073
              RGET    064/69  0/23/027   0027
              ROOTS   064/69  0/23/024   0147
              TGET    064/69  0/23/023   0050
              THAT    072/69  0/23/021   0073
              THIS    101/69  0/23/019   0090
              ZAP     101/69  0/23/017   0093
        C111  CCC     072/69  0/23/015   0093
              CCCC    072/69  0/23/013   0101
        E444  ELECT   100/69  0/23/011   0127
              EPROG   064/69  0/23/010   0032
              ERUPT   100/69  0/23/008   0104
        Q123  QPROG   070/69  0/23/006   0111
              QUICK   072/69  0/23/004   0113
        Z987  THIS    101/69  0/23/002   0090
              Z!!     101/69  0/23/000   0090

        NOTE:  Each line of the DIRECTORY ends with X-Off return linefeed
               allowing a tape to be punched for automatic processing
               under program control.





PURGE


The PURGE Command gives the operator the power to remove the user
library programs and files from the system if they have not been
used since a specified time, thus releasing disc space that would
otherwise be unavailable.  The format of the PURGE Command is as
follows:


             PURGE-day-of-year/year

where

        day-of-year is the day of the year starting with 1
                    and counting in decimal.

        year is the last two digits of the year (i.e., 69 for 1969).



Example of a PURGE Command:

        PURGE-32/69    Removes all programs and files which have not
                       been referenced since February 1st, 1969 (pro-
                       grams which were last used on February 1st will


  remain in the system).

If the date given in the PURGE Command has not yet occurred, then the system
will print the following message:

                       ILLEGAL PARAMETER




Example of PURGE and DIRECTORY Commands

Below, the PURGE Command is repeatedly applied to the example DIRECTORY
given above in order to show how the command works.

       PURGE-65/69

       DIRECTORY
         ID   NAME    DATE    DISC ADR   LENGTH
        A000  ABOUT   100/69  0/23/037   0090
              F3      072/69  0/23/035   0087
              FORGET  100/69  0/23/033   0090
              HELLO   110/69  0/23/032   0027
              PROGN   072/69  0/23/030   0101
              RFET    070/69  0/23/028   0073
              THAT    072/69  0/23/021   0073
              THIS    101/69  0/23/019   0090
              ZAP     101/69  0/23/017   0093
        C111  CCC     072/69  0/23/015   0093
              CCCC    072/69  0/23/013   0101
        E444  ELECT   100/69  0/23/011   0127
              ERUPT   100/69  0/23/008   0104
        Q123  QPROG   070/69  0/23/006   0111
              QUICK   072/69  0/23/004   0113
        Z987  THIS    101/69  0/23/002   0090
              Z!!     101/69  0/23/000   0090


All of the programs with dates 64/69 have been removed (RGET, ROOTS, TGET, EPROG),
but the programs with dates later than 65/69 are still in the system.  The
date of HELLO has been changed from 100/69 to 110/69 (the current date).  The
HELLO date is updated only when a PURGE Command is given, instead of whenever
the HELLO program is referenced, thus making it impossible to PURGE the HELLO
program.  (See Section VI.)




       PURGE-75/69

       DIRECTORY
         ID   NAME    DATE    DISC ADR   LENGTH
        A000  ABOUT   100/69  0/23/037   0090
              FORGET  100/69  0/23/033   0090
              HELLO   110/69  0/23/032   0027
              THIS    101/69  0/23/019   0090
              ZAP     101/69  0/23/017   0093
        E444  ELECT   100/69  0/23/011   0127
              ERUPT   100/69  0/23/008   0104
        Z987  THIS    101/69  0/23/002   0090
              Z!!     101/69  0/23/000   0090

The programs with date 70/69 (RFET, QPROG) and 72/69 (F3, PROGN, THAT, CCC,
CCCC, QUICK) have been deleted from the system.  User-C111 and User-Q123 are
no longer listed in the DIRECTORY because they have no library.


       PURGE-100/69

       DIRECTORY
         ID   NAME    DATE    DISC ADR   LENGTH
        A000  ABOUT   100/69  0/23/037   0090
              FORGET  100/69  0/23/033   0090
              HELLO   110/69  0/23/032   0027
              THIS    101/69  0/23/019   0090
              ZAP     101/69  0/23/017   0093
        E444  ELECT   100/69  0/23/011   0127
              ERUPT   100/69  0/23/008   0104
        Z987  THIS    101/69  0/23/002   0090
              Z!!     101/69  0/23/000   0090


The PURGE Command caused no change in the DIRECTORY.  Programs which were
last used on the PURGE date (100/69) are not purged.




       PURGE-101/69

       DIRECTORY
         ID   NAME    DATE    DISC ADR   LENGTH
        A000  HELLO   110/69  0/23/032   0027
              THIS    101/69  0/23/019   0090
              ZAP     101/69  0/23/017   0093
        Z987  THIS    101/69  0/23/002   0090
              Z!!     101/69  0/23/000   0090

All 100/69 programs have been purged, but 101/69 programs still remain.


       PURGE-110/69

       DIRECTORY
         ID   NAME    DATE    DISC ADR   LENGTH
        A000  HELLO   110/69  0/23/032   0027

This PURGE command specifies the current date (110/69) and eliminates all
programs last used on 101/69.  However, the HELLO program still remains; it
cannot be purged by the operator.