APPENDIX THREE

Atari Timing Values

clock frequency = 1.79 MHZ 1 machine cycle = 0.558 usec. 1 frame = 1/60 second scan lines = 262/frame color clocks = 228/scan line color clocks = 2/machine cycle machine cycles = 29868/frame machine cycles = 114/scan line VBLANK time = 7980 machine cycles or less, depending on GRAPHICS mode. The shortest 6502 instruction requires two cycles; during that time the electron beam moves four color clocks. Horizontal blank time: Wide playfield 18 machine cycles Normal playfield 34 machine cycles Narrow playfield 50 machine cycles See the Hardware Manual for more information on cycle counting.

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