Retro1.org codex

          IDENT  GMSG
          TITLE  GET M860 MESSAGE AND ASSOCIATED DATA.
          ENTRY  GMSG
          ENTRY  GDATA
          SST
*COMMENT GET M860 MESSAGE AND ASSOC. DATA.
          COMMENT  COPYRIGHT CONTROL DATA SYSTEMS INC.  1992.
          SYSCOM B1
 GMSG     SPACE  4
***       GMSG - GET M860 MESSAGE AND ASSOCIATED DATA.
*
*         W. J. STURGIS.     82/09/14.
*
*         GMSG GETS A M860 MESSAGE AND VERIFIES THE CHECKSUM.
*         THE MESSAGE UNPACKED AND RETURNED TO THE CALLER ALONG
*         WITH A STATUS.  ENTRY GDATA RETURNS AN ASSOCIATED DATA
*         BLOCK TO THE CALLER ALONG WITH A STATUS.
*
*         SYMPL CALLS
*         GMSG(FET,MSG,STS);
*         GDATA(FET,DATA,LEN,STS);
*
*         WHERE
*         FET = FET ASSRESS.
*         MSG = MESSAGE BUFFER(UPPER 48 BITS OF 11 WORDS)
*         DATA = ASSOCIATED DATA BUFFER.
*         LEN = LENGTH OF ASSOCIATED DATA.
*         STS = RETURN STATUS.
*                0 = NORMAL COMPLETE.
*                1 = CHECKSUM ERROR(GMSG ONLY).
*                2 = NOT ENOUGH DATA IN BUFFER(BUFFER IS EMPTY).
          SPACE  4,10
*         COMMON DECKS.
 
 
*CALL,COMCMAC
          TITLE  LOCAL MACROS.
**        UPACK - UNPACK ONE MESSAGE WORD.
*
*         UNPACK SC
*
*         WHERE  SC = MASK AND SHIDT COUNT.
 
 
          PURGMAC UNPACK
 
 UPACK    MACRO  SC
          SA1    A1+B1       GET NEXT PACKED WORD
          MX0    SC
          BX2    X0*X1
          LX2    SC-48       POSITION TO LOWER OF PREVOIUS
          BX6    X6+X2
          SA6    B2          STORE UNPACKED WORD
          SB2    B2+B1
          BX6    -X0*X1      LOWER TO NEXT WORD
          LX6    SC          LEFT JUSTIFY
          ENDM
          TITLE  MAIN ROUTINES.
 GMSG     SPACE  0
 GMSG     SUBR               ENTRY/EXIT
          SB1    1
          SX7    A1
          SA7    PARL        SAVE PARAMETER LIST
          SA0    X1          FET ADDRESS
          SB6    MBUF
          SB7    9
          RJ     RDW         READ MESSAGE TO WORKING BUFFER
          ZR     B7,GMS2     IF FULL MESSAGE
          SX6    2           FLAG PARTIAL OR NO MESSAGE
 GMS1     SA1    PARL
          SA1    X1+2
          SA6    X1          STORE RESPONSE
          EQ     GMSGX       RETURN
 
 GMS2     SA1    PARL
          SA1    X1+B1       CALLER MESSAGE BUFFER
          SB2    X1
          SA1    MBUF-1      INITIALIZE A1
          SB3    0           LOOP COUNTER
 GMS3     SA1    A1+B1
          MX0    48
          BX6    X0*X1
          SA6    B2
          SB2    B2+B1
          BX6    -X0*X1
          LX6    48          LEFT JUSTIFY
          UPACK  36
          UPACK  24
          UPACK  12
          SA6    B2          STORE LAST WORD
          SB2    B2+B1
          SB3    B3+B1
          LE     B3,B1,GMS3
          SA1    A1+B1
          MX0    32          ONLY 32 BITS IN LAST WORD
          BX6    X0*X1
          SA6    B2
 
*         CHECKSUM MESSAGE
 
          SB3    B2-10       START OF MESSAGE
          MX0    -16
          BX6    X6-X6       INITIAL CHECKSUM
 GMS4     SA1    B3          MESSAGE WORD
          LX1    16
          BX2    -X0*X1
          IX6    X6+X2
          LX1    16
          BX2    -X0*X1
          IX6    X6+X2
          LX1    16
          BX1    -X0*X1
          IX6    X6+X1
          SB3    B3+B1
          LE     B3,B2,GMS4  IF NOT ENTIRE MESSAGE
          BX6    -X0*X6      IGNORE OVERFLOW
          ZR     X6,GMS1     IF CHECKSUM CORRECT
          SX6    1           RETURN CHECKSUM ERROR STATUS
          JP     GMS1        STORE STATUS AND RETURN
          EJECT
 GDATA    SPACE  0
**        GDATA - GET ASSOCIATED DATA FROM BUFFER.
 
 
 GDATA    SUBR               ENTRY/EXIT
          SB1    1
          SX7    A1
          SA7    PARL        SAVE PARAMETER LIST POINTER
          SA0    X1          FET ADDRESS
          SA1    A1+B1
          SB6    X1          DATA BUFFER
          SA1    A1+B1
          SA1    X1
          SB7    X1          LENGTH
          RJ     RDW         MOVE DATA TO BUFFER
          SX6    B7          REMAINDER WORD COUNT
          ZR     X6,GDA1     IF ALL DATA
          SX6    2           SET NOT FULL BLOCK STATUS
 GDA1     SA1    PARL
          SA1    X1+3
          SA6    X1          STORE RESPONSE
          EQ     GDATAX      RETURN
          TITLE  SUBROUTINES.
 RDW      SPACE  4
**        RDW - READ WORDS TO WORKING BUFFER.
*
**               RDW READS A GIVEN NUMBER OF WORDS FROM A CIRCULAR
*         BUFFER TO A WORKING BUFFER.  RDW IS ADAPTED FROM RDW=(COMCRDW)
*
*         ENTRY  (A0) = ADDRESS OF FET FOR FILE.
*                (B6) = FWA WORKING BUFFER.
*                (B7) = WORD COUNT OF WORKING BUFFER.
*                IF (B7) = 0, NO TRANSFER WILL BE PERFORMED.
*
*         EXIT   (B7) = 0 FOR TRANSFER COMPLETE.
*                (B7) = REMAINING WORDS ON INCOMPLETE TRANSFER.
*
*         USES   X - 1, 2, 3, 4, 6, 7.
*                B - 1, 2, 3, 4, 5, 6, 7.
*                A - 1, 2, 3, 4, 6, 7.
*
*         CALLS  NONE.
 
 
*         PROCESS 1 WORD OR BUFFER EMPTY.
 
 RDW18    ZR     B3,RDWX     IF NO DATA
          BX7    X1          STORE 1 WORD
          SA7    B6
 RDW19    SX6    B4+B3       ADVANCE OUT
          SB4    B4+B3
          SB6    B6+B3
          SB7    B7-B3
          NE     B4,B5,RDW20 IF OUT " LIMIT
          SA1    A0+B1       READ FIRST
          SX6    X1          OUT = FIRST
 RDW20    SA6    A3          UPDATE OUT
          NZ     B7,RDW1     IF NOT DONE
 
 RDW      SUBR               ENTRY/EXIT
 RDW0     SX1    B0+
          LE     B7,RDWX     IF NO WORDS TO TRANSFER
 RDW1     SA3    A0+3        (B4) = OUT
          SA1    A0+2        (B3) = IN
          SB1    1
          SA4    A3+B1       (B5) = LIMIT
          SB4    X3
          SB3    X1
          SA1    X3          READ FIRST WORD
          SB5    X4
          GE     B3,B4,RDW2  IF NO END AROUND
          SB3    B5
 RDW2     SB3    B3-B4       FREE DATA LENGTH
          LE     B3,B7,RDW3  IF NOT ENOUGH ROOM
          SB3    B7
 RDWA     BSS    0
 RDW3     SA3    RDWB        PRESET CMU CODE
          RJ     RDW16       PRESET CMU CODE
*         LE     B3,B1,RDW18 IF 1 WORD OR LESS OF DATA (NO CMU)
*         BX7    X1          (NO CMU)
*         SA1    A1+B1       (NO CMU)
*
*         LE     B3,B1,RDW18 IF 1 WORD OR LESS OF DATA (CMU)
*         JP     RDW14       (CMU)
 
*         INITIALIZE REGISTERS FOR TRANSFER.
 
 RDW4     SX4    B3-B1
          MX6    -3
          SA7    B6
          BX3    -X6*X4      NUMBER OF ODD WORDS
          AX4    3           NUMBER OF BLOCKS
 
*         TRANSFER UP TO 7 WORDS.
 
          ZR     X3,RDW6     IF NO ODD WORDS
          SB2    X3
 RDW5     SB2    B2-B1
          BX7    X1
          SA1    A1+B1
          SA7    A7+B1
          NZ     B2,RDW5     IF MORE WORDS
 
*         PRE-READ REGISTERS.
 
 RDW6     ZR     X4,RDW19    IF NO BLOCKS
          SA2    A1+B1
          SB2    B1+B1       (B2) = 2
          SA3    A2+B1
          SB4    X4          (B4) = LOOP COUNT
          SA4    A3+B1
 
*         TRANSFER 8 WORD BLOCKS.
 
 RDW7     BX6    X1
          LX7    X2
          SA1    A3+B2
          SA2    A4+B2
          SA6    A7+B1
          SB4    B4-B1
          SA7    A6+B1
          BX6    X3
          LX7    X4
          SA3    A1+B2
          SA4    A2+B2
          SA6    A6+B2
          SA7    A7+B2
          BX6    X1
          LX7    X2
          SA1    A3+B2
          SA2    A4+B2
          SA6    A6+B2
          SA7    A7+B2
          BX6    X3
          LX7    X4
          SA3    A1+B2
          SA4    A2+B2
          SA6    A6+B2
          SA7    A7+B2
          NZ     B4,RDW7     LOOP
 
*         READ EXIT.
 
          SA3    A0+3        OUT
          SA1    A3+B1       (B5) = LIMIT
          SB5    X1
 RDW8     SB6    B6+B3
          SB7    B7-B3
          SB4    X3+B3       ADVANCE OUT
          SX6    X3+B3
          SA1    A0+1        READ FIRST
          NE     B4,B5,RDW20 IF OUT " LIMIT
          SX6    X1+         OUT = FIRST
 RDW9     EQ     RDW20       CLEAN UP AND RETURN
 
*         MOVE DATA WITH CMU.
 
 RDW14    SX4    B3-819
          PL     X4,RDW15    IF MOVE TOO BIG FOR CMU
          SX4    B3          10 * WORDS = CHARACTERS
          LX6    X4,B1
          BX1    X0          SAVE X0
          LX4    3
          IX6    X4+X6
          SX7    B6          SET DESTINATION ADDRESS
          LX3    30
          MX4    -4
          BX7    X7+X3
          BX3    X4*X6       EXTRACT UPPER PORTION OF CHARACTER COUNT
          LX3    48-4
          BX4    -X4*X6
          BX7    X3+X7
          LX4    26
          BX7    X4+X7
          AX3    51
          SA7    RDWB        STORE DESCRIPTOR WORD
          IM     RDWB        MOVE DATA
          BX0    X1          RESTORE X0
          ZR     X3,RDW19    IF NO READ EXIT CHECK
          SX3    B4          SET OUT
          JP     RDW8
 
 RDW15    BX7    X1
          SA1    A1+B1
          JP     RDW4
 
*         PRESET FOR CMU.
*         RDWB IS READ UP AND THEN RETURN JUMPED TO IN ORDER TO VOID
*         THE INSTRUCTION STACK.
 
 RDWB     LE     B3,B1,RDW18  IF 1 WORD OR LESS (CMU)
          JP     RDW14
 
 RDW16    EQU    RDWB        USED TO VOID STACK AT PRESET
 
*         PRESET FOR CMU.
 
          SA4    CMUR        CHECK IF CMU AVAIALABLE
          SB3    RDWA
          NG     X4,RDW17    IF CMU
          SA3    RDWC
 RDW17    BX6    X3
          SA6    B3
          JP     RDW1
 
 RDWC     LE     B3,B1,RDW18  IF 1 WORD OR LESS (NO CMU)
          BX7    X1
          SA1    A1+B1
          TITLE  WORKING STORAGE.
*         WORKING STORAGE.
 
 
 PARL     BSS    1           PARAMETER LIST POINTER
 MBUF     BSS    9           MESSAGE BUFFER
          SPACE  4
          END