D D D D Do
LDA 01 STA GALIVE STA GALIVE 1 STA GALIVE 2 STA GALIVE 3 SETUP COLOR REGISTERS LDA 00 STA C0L0R4 LDA 24 STA COLORO LDA 46 STA COLORI BACKGROUND BLACK TAN FOR PLAYFIELD 0 LT RED FOR PLAYFIELD 1 LDA 08 STA HSCROL LDA 00 STA SLTIME STA SLTIME1 STA SETIME STA REZFLAG STA EXCOUNT LDA 00 STA AUDC3 STA AUDCTL LDA 03 STA SKCTL LDA 30 STA TDELAY1 LDA 50 STA TDELAY2 LDA 00 STA TMISO STA TMIS1 STA TMIS2 STA DELAY STA HITCLR STA BOMBON PUT IN GROUND TARGETS SET FINE SCROLL HI SO SCREEN LEFT EDGE CLEAR...
Vertical Blank Interrupts
The Atari computers use the Vertical Blank Interrupt for many housekeeping chores. When the Atari is first powered up under normal conditions, the Vertical Blank Interrupt is enabled. A special list of vectors is placed in page two of memory. The operating system places the list of vectors in page two because these are RAM locations and the user can change their contents to point to his own interrupt service routine. System Reset is the only interrupt that cannot be routed through page two. The...