Classic Computer Magazine Archive ANTIC VOL. 1, NO. 3 / AUGUST 1982

Systems Guide

Memory Map

Page 2 Continued

by James Capparell

Memory Map is an on-going feature of ANTIC. We intend to publish the function of all the low memory RAM locations. The format for our description is:

12$C2DOSINIThe Operating System variable called DOSINI uses 2 contiguous locations starting at address 12 (decimal) or C (hexidecimal).

566$2364SPARENo Operating System Function.
573$23D1CAUX2Command auxiliary byte.
574$23E1TEMPReceives one-byte responses from serial bus controllers.
575$23F1ERRFLGError flag any device error except timeout errors.
576$2401DFLAGSDisk flags from sector 1, contains value of first byte of boot file.
577$2411DBSECTNumber of disk boot sectors.
578$2422BOOTADAddress where disk boot loader will be put.
580$2441COLDSTColdstart flag when = 1 then powerup in progress. When = 0 then S / RESET in progress. If set = 1 during norm program execution then S / RESET will act like powerup giving some protection.
581$2451SPARENo Operating System Function.
582$2461DSKTIMDisk timeout register.
583$24740LINBUFCharacter line buffer used to temporarily buffer one physical line of text when screen editor is moving screen data
626$26F1 GPRIORGlobal priority shadow for PRIOR [$DOlB] controls priority of player/missile/playfield.
PADDL7Potentiometer 0 - 7 storage.
STICK3Joystick 0 - 3 values.
PTRIG7Paddle trigger 0 - 7.
644$2844STRIG0Joystick trigger 0 - 3.
648$2881CSTATNo Operating System Function.
649$281WMODEUsed by cassette handler as read/write mode flag. 0 = read; $80 = write.
650$28A1BLIMCassette record data size Count of # of data bytes being read range 1-128 depends on record control byte.
651$28B4SPARENo Operating System Function.
656$2901TXTROWText row cursor range 0-3.
657$2912TXTCOLText column cursor range 0-39 used in split screen. These two variables give cursor position.
659$2931TINDEXSplit screen text window index always = 0 when SWPFLG[78] = 0 equivalent of DINDEX.
660$2942TXTMSCSplit screen text window version SAVMSC[58].
662$2966TXTOLDOldrow and old column for text and then some split screen cursor data.
668$29C1TMPXI? ?
669$29D1HOLD3Used by the display handler to hold scroll loop counter.
670$29E1SUBTMP? ?
671$29F1HOLD2? ?
672$2A01DMASK? ?

To be continued