By CARL EVANS
USEFUL POKE & PEEK LOCATIONS : PART I
18,19,20 Clock; address 20 increments 60 times a second; 19 increments each time location 20 is reset (about once every 4.25 seconds); 18 increments each time location 19 is reset (about once every 18 minutes) 65 POKE a zero here to stop normal program loading sounds (Beeping) 77 POKE a zero here to turn off the attract mode; must repeat every seven to nine minutes. 82 Screen left margin (default=2) 83 Screen right margin (default = 38) 84 Current cursor row (Graphics 0) 85,86 Current cursor column for all modes (ranges from 0 to 319) 88,89 Upper left-hand screen corner address 93 Code for the character under the cursor 128,129 BASIC's LOMEM pointer 130,131 Contains location of the Variable Name Table 132,133 Points to the end of the Variable Name Table plus one byte 134,135 Contains location of the Variable Value Table 136,137 Points to the beginning of a BASIC program 140,141 Contains location of the String and Array Table; also the end of a BASIC program 144,145 BASIC's top of memory pointer 186,187 The line number where a BASIC program has stopped due to ERROR, TRAP, STOP or BREAK 195 The OS code for an error during execution is stored here 212,213 Used to return a value from a USR call 560,561 Contains the location of the display list 580 POKE a 1 here to cause a reboot when [RESET] is pressed 624 Contains current value of PADDLE0 (0-228) 625 PADDLE1 626 PADDLE2 627 PADDLE3 628 PADDLE4 629 PADDLE5 630 PADDLE6 631 PADDLE7 632 Contains current value of STICK0 633 STICK1 634 STICK2 635 STICK3 636 PTRIG0: contains 0 if PADDLE0 trigger is pressed; otherwise contains 1 637 PTRIG1 638 PTRIG2 639 PTRIG3 640 PTRIG4 641 PTRIG5 642 PTRIG6 643 PTRIG7 644 STRIG0: contains 0 if STICK0 trigger is pressed; otherwise contains 1 645 STRIG1 646 STRIG2 647 STRIG3 660,661 Contains address of upper left corner of text window 694 Inverse video flag: 0=normal, 128 = inverse 702 Caps-lock flag: 0=lowercase, 64=uppercase, 128=control characters 708 COLOR0: used for the color of upper-case characters in Graphics 1 and 2 (default is 40) 709 COLOR1: used for the color of lowercase characters in Graphics 1 and 2 (default is 202) 710 COLOR2: used for the color of inverse uppercase in Graphics 1 and 2 used for background in Graphics 0 (default is 148) 711 COLOR3: used for the color of inverse lowercase in Graphics 1 and 2 (default is 70) 712 COLOR4: used for the color of the background (border) in Graphics 0 (default is: 0) 736,737 Used by DOS to hold the RUN address of a binary load file 738,739 Immediate execution address used by DOS to hold the INIT address of a binary load file 741,742 MEMTOP for BASIC: and the OS (minus 1 to get highest free memory) 743,744 MEMLO points to the bottom of user memory for BASIC programscontinued next month
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