Type ASSEMBLE
Source Lines : 737
Fixes Applied : 1
Most Recent Version : Tuesday, December 12, 1978
Last Fix ID : [R10475DS]
Module
DMSDSK (DISK)
Function
TO DUMP A DISK FILE TO CARDS, OR TO LOAD FILES FROM
CARDS TO DISK.
Attributes
TRANSIENT (WITH SYSTEM OPTION); SERIALLY REUSABLE.
Operation
THE OPERATION OF DISK DEPENDS ON WHETHER THE CALLING
PROGRAM SPECIFIES DUMP OR LOAD.
DUMP: DISK COPIES THE FILE DESIGNATION FROM THE
PARAMETER LIST INTO BYTES 58 - 76 OF AN 89-BYTE
BUFFER. (THE FIRST FOUR BYTES OF THE BUFFER CONTAIN
AN IDENTIFIER CONSISTING OF AN INTERNAL
REPRESENTATION OF A 12-2-9 PUNCH AND THE CHARACTERS
'CMS'.) THEN DISK TEMPORARILY CHANGES THE
CHARACTERISTICS OF THE FILE IN THE 40-BYTE FST ENTRY
TO MAKE IT APPEAR AS A FILE OF 800-BYTE FIXED-LENGTH
RECORDS. (THE CORRECT FST ENTRY IS RESTORED WHEN THE
FILE HAS BEEN DUMPED, OF COURSE.) DISK MOVES THE
INITIAL VALUE FOR SEQUENCING
(001) INTO BYTES 77-80 OF THE BUFFER. DISK NEXT
CALLS THE DMSBRD FUNCTION
PROGRAM TO READ THE FIRST 50 BYTES OF THE TEMPORARY
COPY INTO
BYTES 6-55 OF THE BUFFER AND THEN THE DMSCIO FUNCTION
PROGRAM TO PUNCH
THE CONTENTS OF THE BUFFER. HAVING PUNCHED THE FIRST
CARD, DISK INCREMENTS THE SEQUENCE NUMBER (BYTES
77-80 OF THE OUTPUT BUFFER) AND OVERLAYS BYTES 6-55
OF THE BUFFER WITH THE NEXT 50 BYTES OF THE FILE
BY CALLING DMSBRD. IT THEN PUNCHES THE CONTENTS OF
THE
BUFFER. DISK REPEATS THIS PROCESS FOR EACH
SUBSEQUENT 50 BYTES OF DATA IN THE TEMPORARY DISK
FILE. WHEN THE END-OF-FILE IS ENCOUNTERED, DISK
GENERATES AN END CARD (ONE WITH N IN COLUMN 5) AND
PUNCHES IT,