GR

* 0078-001-H102 (G$DR) DRAWING NO. 41285543-001-03 PAGE 3

0101 * 1 MAIN PROGRAM (USUALLY STARTING AT '1000) 0102 * 0103 * 2 APPROPRIATE INPUT-OUTPUT SUPERVISOR 0104 * 0105 * 3 AS MANY INDIVIDUAL INPUT-OUTPUT LIBRARY ROUTINES AS 0106 * REQUIRED, DEPENDING ON THE HARDWARE OPTIONS AVAILABLE 0107 * 0108 * 4 G$DR 0109 * 0110 * G$DR MUST BE LOADED LAST AS IT ASSUMES THAT THE REST OF THE 0111 * CORE STORE (STARTING AT LOCATION G$FF (FIRST FREE LOCATION) 0112 * CAN BE USED BY THE CALLING PROGRAM AS WORKSPACE AT RUN TIME. 0113 * 0114 * CARE SHOULD BE TAKEN TO SELECT THE CORRECT DESECTORING MODE. 0115 * IF THE PROGRAM IS TO WORK ON COMPUTERS HAVING NOT MORE THAN 0116 * 16 384 WORDS OF CORE STORE, OR IF ANY ONE OR MORE OF THE 0117 * CONSTITUENT MODULES IS RESTRICTED TO 16K WORKING BY, FOR 0118 * EXAMPLE, SIMULTANEOUS USE OF INDEXING AND INDIRECT, THEN ALL 0119 * LOADING SHOULD BE CARRIED OUT IN LXD MODE, E.G. BY ENTERING 0120 * LDR-APM AT 'XX000. CONVERSELY, IF THE PROGRAM WILL ONLY BE 0121 * USED ON COMPUTERS WITH MORE THAN 16 384 WORDS OF CORE STORE, 0122 * AND ALL MODULES ARE WRITTEN IN UNIVERSAL MODE, THE LOADING 0123 * MAY BE CARRIED OUT IN EXD MODE, E.G. BY ENTERING LDR-APM AT 0124 * 'XX006. 0125 * 0126 * IF DESECTORING IN THE CURRENT BASE SECTOR IS TO BE AVOIDED, 0127 * DO NOT LOAD G$DR ACROSS A SECTOR BOUNDARY. 0128 * 0129 * 0130 * GENERIC DUMMY ROUTINE 0131 * 0132 * THIS ENTRY MAY BE USED BY AN INPUT-OUTPUT SUPERVISOR PROGRAM 0133 * TO DETERMINE THE ADDRESS AND SIZE OF THE FREE CORE AREA 0134 * AVAILABLE FOR USE AS WORKSPACE SUCH AS A COMPILER SYMBOL 0135 * TABLE. THE CALLING SEQUENCE IS: 0136 * 0137 * CALL G$DR GENERIC DUMMY ROUTINE 0138 * NORMAL RETURN WITH THE A- 0139 * REGISTER CONTAINING THE 0140 * ADDRESS OF THE FIRST FREE 0141 * LOCATION, AND THE X-REGISTER 0142 * CONTAINING MINUS THE NUMBER OF 0143 * FREE LOCATIONS UP TO THE TOP 0144 * OF MEMORY ACTUALLY AVAILABLE 0145 * IN THE OBJECT COMPUTER. 0146 * EXTENDED ADDRESSING WILL HAVE 0147 * BEEN ENABLED OR DISABLED. 0148 * 0149 * 0150 * DEFAULT INPUT-OUTPUT ROUTINES