          EJECT
*         CTEXT CTP$DFT MAIN LOOP PACKETS.
*
*         THIS DECK DEFINES PACKET CONTROL VARIABLES AND A ROUTINE TO
*         CHECK PACKET STATUS.


 CPC      SUBR               ENTRY/EXIT
          CALL   CPS         CHECK PACKET STATUS
          UJN    CPCX        RETURN
 PKTS     SPACE  4,20
**        PACKET CONTROL WORDS.
*
*         *CELCW* CONTROLS CONSOLE LOGGING, AND *PKTCW* CONTROLS
*         GENERAL PACKET TRAFFIC.  CONSOLE LOGGING HAS A HIGHER
*         PRIORITY THAN GENERAL TRAFFIC.
*
*         NOTE - *PKTCW* CAN ONLY QUEUE ONE REQUEST.  IF PACKETS OTHER
*         THAN CONSOLE LOGGING BECOME NUMEROUS OR FREQUENT, THIS MAY NEED
*         TO BE MODIFIED.
*
*         *DI4CW* CONTROLS THE PHASES OF LOADING *DFT* INTO THE
*         SECONDARY IOU.  THIS CONTROL IS NEEDED ON THOSE MACHINES
*         WHICH HAVE DUAL IOU-S.
*
* CELCW   1/R, 1/T, 2/, 6/ PHASE, 6/ MRB
*
*         R = RESPONSE PENDING.
*         T = PACKET TIMEOUT OCCURRED.
*         PHASE = LOGGING PHASE (SEE ROUTINE *LTC* FOR DETAILS.)
*         MRB = MAINTENANCE REGISTER BUFFER NUMBER TO LOG (BEING LOGGED).
*             = 77, IF MRT IS TO BE LOGGED (BEING LOGGED).
*
*
* PKTCW   1/R, 1/T, 2/0, 2/C, 1/S, 1/P, 8/REQUEST
*
*         R = RESPONSE PENDING.
*         T = PACKET TIMEOUT OCCURRED.
*         C = OFFSET TO PACKET CONTROL WORD FOR TIMING (2).
*         S = 1, IF SEQUENCE BYTE IS IN UPPER PART OF PACKET.
*         P = 1 IF PHASED PACKET OPERATION IN PROGRESS.
*         REQUEST = *PKR__*, IF PACKET REQUEST PRESENT.
*
*
* DI4CW   1/R, 1/T, 1/P, 1/0, 12/ PHASE
*
*         R = RESPONSE PENDING.
*         T = PACKET TIMEOUT OCCURRED.
*         P = 1, IF PROCESSING REQUEST TO START *DFT-S*.
*         PHASE = PHASE OF PROCESSING IN STARTING UP DFT-S.


 TPKT     BSS    0           START OF TABLE OF PACKET CONTROL WORDS
 CELCW    BSS    1           CONSOLE LOGGING CONTROL WORD
 PKTCW    BSS    1           GENERAL PACKETS CONTROL WORD
 DI4CW    CON    0           DUAL I4 DEADSTART PACKET CONTROL WORD
 TPKTL    EQU    *-TPKT      NUMBER OF PACKET CONTROL WORDS
          SPACE  4,10
**        ADDITIONAL GLOBAL PACKET DATA ITEMS.

 PES1     CON    0           PACKET ERROR STATUS
 PKERR    CON    0           LAST RESPONSE PACKET ERROR CODE
 PKTIM    CON    0           4/INDEX TO CW, 12/ELAPSED TIME IN SECONDS
 PKTCW1   CON    0           FIRST WORD OF PACKET CONTROL ROUTINE ADDRESS
 PKTCW2   CON    0           SECOND WORD OF PACKET CONTROL ROUTINE ADDRESS
 PKTPH    CON    0           PKTCW PHASE BEING PROCESSED

*         END    CTP$DFT MAIN LOOP PACKETS
