1 
 2 /* BEGIN include file imp_leader.incl.pl1                                       */
 3 
 4 /*             This include file defines the format of the message leader       */
 5 /*        passed between the IMP and the HOST (in either direction).  Because   */
 6 /*        the IMP DIM also does the fabrication and interpretation of NCP       */
 7 /*        leaders, we include that definition here also.                        */
 8 
 9      declare
10           1 imp_leader based,                               /* Structure of leader of IMP<->HOST messages     */
11              2 local_flags,                                 /* these are internally used only       */
12                 3 processing_switch bit (1),                /* if we have already processed this message      */
13                 3 unassgn1 bit (3),
14              2 format_flag bit (4),                         /* set to 15 (111b) to indicate new format        */
15              2 network bit (8),                             /* currently must be set to zeroes                */
16              2 unassgn2 bit (4),
17              2 trace bit (1),                               /* could be used to indicate IMP-by-IMP trace     */
18              2 leader_flags bit (3),                        /* could be used for special meanings             */
19              2 type bit (8),                                /* message type                                   */
20              2 handling_type bit (8),                       /* message sub-type or status field               */
21              2 host bit (8),                                /* destination or source host number              */
22              2 imp bit (16),                                /* destination or source IMP            */
23              2 message_id,                                  /* id of the message as known to network          */
24                 3 link bit (8),                             /* old-style link number                          */
25                 3 sub_link bit (4),                             /* rest of message id field                   */
26              2 sub_type bit (4),                            /* further refined certain message types          */
27              2 msg_length bit (16);                         /* length of message in bits                      */
28 
29      declare
30           1 ncp_leader based,                               /* message leader as used for NCP messages        */
31              2 impleader like imp_leader,
32              2 unassgn3 bit (8),
33              2 byte_size bit (8),                           /* byte-size of NCP connection                    */
34              2 byte_count bit (16),                         /* count of data bytes in this NCP message        */
35              2 unassgn4 bit (8);
36 
37 /* END INCLUDE FILE imp_leader.incl.pl1                                         */
38