/       BINARY PATCHES TO FOCAL           PAL8-VB0  23-JUL-86 PAGE 1

   1                 /       BINARY PATCHES TO FOCAL
   2   
   3                 /       LAST EDIT:      15-MAY-1986     18:00:00        CJL
   4   
   5                 /       MAY BE ASSEMBLED WITH '/J' SWITCH SET.
   6   
   7                 /       THIS FILE IS A ONE-PAGE COLLECTION OF PATCHES TO FOCAL TO IMPLEMENT THREE
   8                 /       FUNCTIONS:
   9   
  10                 /       1):     FBLK(BLOCK[,WRITE-INDICATOR])
  11                 /       2):     FWRD(ADDRESS[,REPLACEMENT VALUE])
  12                 /       3):     FAND(FIRST-ARGUMENT[,SECOND-ARGUMENT])
  13   
  14                 /       DESCRIPTION OF FUNCTIONS:
  15   
  16                 /       FUNCTION "FBLK" READS (OR WRITES) A SET OF DISK BLOCKS STARTING FROM THE
  17                 /       BLOCK NUMBER EVALUATED FROM THE FIRST ARGUMENT. THE FUNCTION WILL CAUSE
  18                 /       A READ OPERATION IF ONE ARGUMENT IS GIVEN; MERELY GIVING A SECOND
  19                 /       ARGUMENT CAUSES A WRITE OPERATION (THE ARGUMENT VALUE IS UNIMPORTANT).
  20                 /       THE MEMORY AFFECTED BY THE TRANSFER IS LOCATION 0000 ONWARD IN FIELD
  21                 /       "BUFFLD." THE NUMBER OF BLOCKS TRANSFERRED IS DETERMINED BY "N." THE
  22                 /       LOGICAL I/O UNIT IS DETERMINED BY "UNIT."
  23   
  24                 /       FUNCTION "FWRD" RETURNS THE CONTENTS OF THE SPECIFIED MEMORY ADDRESS
  25                 /       EVALUATED FROM THE FIRST ARGUMENT. IF A SECOND ARGUMENT IS PASSED, THEN
  26                 /       ITS EVALUATION BECOMES THE REPLACEMENT VALUE AT THE SPECIFIED ADDRESS.
  27                 /       THE "FWRD" FUNCTION CAN BE CONDITIONALLY ASSEMBLED TO TREAT THE FIRST
  28                 /       ARGUMENT AS A TWELVE BIT ADDRESS OF A TWELVE BIT NUMBER OR AN ELEVEN BIT
  29                 /       ADDRESS OF A TWENTY-FOUR BIT NUMBER.
  30   
  31                 /       FUNCTION "FAND" RETURNS THE LOGICAL BIT-WISE AND OF THE TWO ARGUMENTS
  32                 /       PASSED TO IT. IF THE SECOND ARGUMENT IS NOT PRESENT, IT IS TREATED AS
  33                 /       ZERO AND CAUSES A ZERO RETURN VALUE.
  34   
  35                 /       ASSEMBLY INSTRUCTIONS:
  36   
  37                 /       SET "ADR" TO 0 FOR 12-BIT ADDRESSING, 1 FOR 24-BIT ADDRESSING (DEFAULT IS 0).
  38   
  39                 /       SET "BUFFLD" TO THE PROPER FIELD FOR "FBLK", "FWRD" (DEFAULT IS 40).
  40   
  41                 /       SET "N" TO THE I/O CALL LENGTH DESIRED IN "FBLK" (DEFAULT IS 00 WHICH
  42                 /       USES 40 BLOCKS).
  43   
  44                 /       SET "UNIT" TO THE DESIRED I/O UNIT (DEFAULT IS 7).