707
edits
NTSC Spectrum: Difference between revisions
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Use ÷ for division
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m (Use ÷ for division) |
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* The CPU is clocked at 3.5275 MHz. | * The CPU is clocked at 3.5275 MHz. | ||
* The ULA is a model 6C011E-3 (dated 8501 in the example in question) which generates a NTSC frame size and rate. | * The ULA is a model 6C011E-3 (dated 8501 in the example in question) which generates a NTSC frame size and rate. | ||
* One frame lasts 0xe700 (59136) T-states, giving a frame rate of 3.5275×10<sup>6</sup> | * One frame lasts 0xe700 (59136) T-states, giving a frame rate of 3.5275×10<sup>6</sup> ÷ 59136 = 59.65 Hz. | ||
* 224 T-states per line implies 264 lines per frame. | * 224 T-states per line implies 264 lines per frame. | ||
* The first [[Contended memory|contended cycle]] is at 0x22ff (8959). This implies 40 lines of upper border, 192 lines of picture and 32 lines of lower border/retrace. | * The first [[Contended memory|contended cycle]] is at 0x22ff (8959). This implies 40 lines of upper border, 192 lines of picture and 32 lines of lower border/retrace. | ||