Retro1.org codex

*DECK     NVFIIVT 
USETEXT  TXVCBNV
PROC NVFIIVT; 
# TITLE NVFIIVT - INITIALIZES THE VOT AND VDT TABLES #
 
      BEGIN    # NVFIIVT #
# 
**    NVFIIVT - INITIALIZES THE VOT AND VDT TABLES
* 
*     A. LIM           81/08/07 
* 
*     THIS PROCEDURE INITIALIZES THE VCB-ORDINAL-TABLE(VOT) AND 
*     THE VCB-DATA-VALID-INDICATOR-TABLE(VDT).
* 
*     PROC NVFIIVT
* 
*     ENTRY    NONE 
* 
*     EXIT     VOT IS INITIALIZED TO FREE STATE, WHILE
*              VDT IS INITIALIZED TO INVALID STATE. 
* 
*     NOTES    NONE 
* 
*     METHOD   PHYSICAL FEATURES OF THE FILES SUCH AS THE 
*              MAXIMUM-SECTOR-PER-TRACK(MST), MAXIMUM-
*              ENTRIES-PER-SECTOR(MES), ACTUAL-ENTRIES- 
*              PER-SECTOR(AES), BITS-USED-IN-WORD, AND
*              WORDS-PER-TABLE, ARE DEFINED IN TXVCBNV. 
*              FIRST, A BIT PATTERN OF MES BITS WITH AES
*              BITS SET IS BUILT.  FOR EXAMPLE, MES = 8,
*              AND AES = 7, THEN THE BIT PATTERN WOULD
*              LOOK LIKE THIS: 11111110.
*              FINALLY THE VOT AND THE VDT TABLES WOULD BE
*              SET TO THE BIT PATTERN A BYTE AT A TIME
*              UNTIL MST TIMES IS EXHAUSTED.
* 
# 
 
 
#     ITEMS      #
 
      ITEM BITPTN     U;               # BIT PATTERN                   #
      ITEM I,J,K,L    I;               # INDUCTION VARIABLES           #
      ITEM SECWORD    U;               # SECTORS/WORD                  #
      ITEM WRDS       U;               # VOT AND VDT TABLE SIZE        #
      ITEM WD         U;               # THE NTH WORD IN THE TABLE     #
 
 
CONTROL EJECT;
 
      SECWORD = BITSWORD$/MAXENSEC$;  # CAL SECTORS/WORD               #
      WRDS = (MAXSEC$ + SECWORD - 1)/SECWORD;  # CAL TBL SIZ(VTSIZE$)  #
 
#     SET BIT PATTERN                  #
 
      FOR I = 0 STEP 1 UNTIL MAXENSEC$ - 1 DO 
        BEGIN 
        IF I LQ ACTENSEC$ - 1 THEN
          BEGIN 
          B<I,1>BITPTN = 1; 
          END 
        ELSE
          BEGIN 
          B<I,1>BITPTN = 0; 
          END 
        END                            # FOR LOOP                      #
 
# 
*     INITIALIZES VOT AND VDT A BYTE AT A TIME WITH THE 
*     AFORE-DEFINED BIT PATTERN 
# 
 
      FOR J = 1 STEP SECWORD UNTIL MAXSEC$ DO 
        BEGIN 
        WD = J/SECWORD; 
        K = MAXSEC$ - WD * SECWORD; 
        IF K GR SECWORD THEN
          BEGIN 
          K = SECWORD;
          END 
        FOR L = 0 STEP 1 UNTIL K - 1 DO 
          BEGIN 
          B<12+L*MAXENSEC$, MAXENSEC$>VOT$WORD[WD] =
                                 B<0, MAXENSEC$>BITPTN; 
          B<12+L*MAXENSEC$, MAXENSEC$>VDT$WORD[WD] =
                                 B<0, MAXENSEC$>BITPTN; 
          END                          # FOR L LOOP                    #
        END                            # FOR J LOOP                    #
      RETURN; 
      END    # NVFIIVT #
 TERM