We will create the WTO SVC to queue messages to the console. \u00a0When the SVC is called Register 1 contains the address of the message in the bottom three bytes (24 bit address) and the high order byte contains the length of the message. \u00a0If the message length is greater than 79 bytes it will be truncated. \u00a0If it is less than 79 bytes it will be padded with blanks.<\/p>\n
000000 14 S035WTO CSECT , \r\n000000 18CF 15 LR R12,R15 SET UP \r\n 00000 16 USING S035WTO,R12 BASE REGISTER \r\n 17 *\r\n000002 18B1 18 LR R11,R1 COPY PARM REGISTER\r\n000004 58A0 0010 00010 19 L R10,16 CVT\r\n000008 58A0 A014 00014 20 L R10,CVTCCB-@CVT(,R10) CONSOLE COMMUNICATION BLOCK \r\n 00000 21 USING @CCB,R10 \r\n 22 * \r\n00000C 12AA 23 LTR R10,R10 DO WE HAVE A CONSOLE \r\n00000E 4780 C09A 0009A 24 BZ WTO900 NO - GO ABEND \r\n 25 * \r\n000012 26 WTO010 DS 0H \r\n000012 5890 A008 00008 27 L R9,CCBFMQ GET FREE BUFFER \r\n000016 1299 28 LTR R9,R9 AND FREE\r\n000018 4780 C0A2 000A2 29 BZ WTO910 NO - CAN'T DO \r\n 30 * \r\n00001C 5820 9000 00000 31 L R2,0(,R9) FWD CHAIN PTR \r\n000020 BA92 A008 00008 32 CS R9,R2,CCBFMQ REMOVE FROM CHAIN\r\n000024 4770 C012 00012 33 BNZ WTO010 \r\n 34 * \r\n 00000 35 USING @CMB,R9<\/pre>\nFirst we locate the CCB and take a message buffer off the free buffer queue. \u00a0If no free buffers are available we abend.<\/p>\n
000028 D703 9000 9000 00000 00000 37 XC CMBNEXT,CMBNEXT CLEAR FWD CHAIN PTR\r\n00002E 181B 38 LR R1,R11 COPY\r\n000030 182B 39 LR R2,R11 PARM VALUE\r\n000032 8810 0018 00018 40 SRL R1,24 SHIFT DOWN TO GET LENGTH\r\n000036 1211 41 LTR R1,R1 CHECK LENGTH\r\n000038 4780 C0AA 000AA 42 BZ WTO920 ERROR IF ZERO\r\n 43 *\r\n00003C 5910 C0C0 000C0 44 C R1,=F'79' CHECK MAX LENGTH \r\n000040 4740 C048 00048 45 BL WTO020\r\n 46 *\r\n\f000044 4110 004F 0004F 47 LA R1,79\r\n000048 48 WTO020 DS 0H \r\n000048 0610 49 BCTR R1,0 SUBTRACT ONE FOR EX\r\n00004A 9240 9004 00004 50 MVI CMBTEXT,C' ' CLEAR OUT MESSAGE BUFFER\r\n00004E D24D 9005 9004 00005 00004 51 MVC CMBTEXT+1(L'CMBTEXT-1),CMBTEXT\r\n000054 4410 C094 00094 52 EX R1,WTOEX COPY IN TEXT<\/pre>\nThe message text is copied into the free buffer.<\/p>\n
000058 54 WTO030 DS 0H \r\n000058 4120 A004 00004 55 LA R2,CCBMBQ CONSOLE MESSAGE QUEUE\r\n00005C 56 WTO040 DS 0H \r\n00005C 5810 2000 00000 57 L R1,0(,R2) NEXT ELEMENT\r\n000060 1211 58 LTR R1,R1\r\n000062 4780 C06C 0006C 59 BZ WTO050 BRANCH IF LAST ELEMENT \r\n 60 * \r\n000066 1821 61 LR R2,R1 NEXT ELEMENT \r\n000068 47F0 C05C 0005C 62 B WTO040\r\n 63 * \r\n00006C 65 WTO050 DS 0H \r\n00006C BA19 2000 00000 66 CS R1,R9,0(R2) ADD TO CHAIN\r\n000070 4770 C058 00058 67 BNZ WTO030 GO TRY AGAIN<\/pre>\nThe free buffer is placed on the message queue at the end of the chain.<\/p>\n
000074 9140 A00C 0000C 69 TM CCBECB,X'40' ECB ALREADY POSTED ?\r\n000078 4710 C08A 0008A 70 BO WTO060 YES - SKIP POST\r\n 71 * \r\n00007C 4110 A00C 0000C 72 LA R1,CCBECB\r\n 73 @CALL POST\r\n000080 58F0 0014 00014 74+ L R15,20 MVT ADDRESS \r\n000084 58F0 F028 00028 75+ L R15,MVTPOST-@MVT(,R15) ROUTINE ADDRESS \r\n000088 05EF 76+ BALR R14,R15\r\n 77 * \r\n00008A 78 WTO060 DS 0H \r\n 79 @CALL EXIT \r\n00008A 58F0 0014 00014 80+ L R15,20 MVT ADDRESS\r\n00008E 58F0 F024 00024 81+ L R15,MVTEXIT-@MVT(,R15) ROUTINE ADDRESS\r\n000092 05EF 82+ BALR R14,R15 \r\n 84 * \r\n000094 D200 9004 B000 00004 00000 85 WTOEX MVC CMBTEXT(0),0(R11) EXECUTED MOVE<\/pre>\nIf the ECB is already posted we can go ahead and exit now. \u00a0If the ECB is not posted we call the Post routine to post it and then we exit the SVC.<\/p>\n
00009A 88 WTO900 DS 0H \r\n00009A 4110 0123 00123 89 LA R1,X'123' NO CONSOLE DEFINED\r\n00009E 47F0 C0B2 000B2 90 B WTO999\r\n 91 *\r\n0000A2 92 WTO910 DS 0H \r\n0000A2 4110 0223 00223 93 LA R1,X'223'\r\n0000A6 47F0 C0B2 000B2 94 B WTO999 \r\n 95 *\r\n0000AA 96 WTO920 DS 0H\r\n\f0000AA 4110 0323 00323 97 LA R1,X'323'\r\n0000AE 47F0 C0B2 000B2 98 B WTO999\r\n 99 * \r\n0000B2 100 WTO999 DS 0H \r\n 101 @CALL ABEND \r\n0000B2 58F0 0014 00014 102+ L R15,20 MVT ADDRESS\r\n0000B6 58F0 F020 00020 103+ L R15,MVTABEND-@MVT(,R15) ROUTINE ADDRESS\r\n0000BA 05EF 104+ BALR R14,R15<\/pre>\nHere are the various abend codes if something goes wrong.<\/p>\n
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We will create the WTO SVC to queue messages to the console. \u00a0When the SVC is called Register 1 contains the address of the message in the bottom three bytes (24 bit address) and the high order byte contains the … Continue reading