42 lines
1.9 KiB
Plaintext
42 lines
1.9 KiB
Plaintext
CPU (p/n: RP2A03G) [Made by Kevin Horton (khorton@iquest.net)]
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Pins 39,38, and 37 correspond to STA $4016 bits D0,D1, and D2 resp.
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Pin 36 goes low during an LDA $4016, and pin 35 goes low during an
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LDA $4017.
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Audio 1 is the output for the two squarewave channels, and
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Audio 2 is the output for triangle, noise, and PCM.
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Audio outputs are raw. What you hear coming out of the NES is mixed and has
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passed through filters.
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The NES's CPU is considered to lack decimal mode.
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.----\/----.
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Audio 1 - |01 40| - +5V
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Audio 2 - |02 39| - Strobe on sticks
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/RST - |03 38| - Exp. conn pin #44
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A0 - |04 37| - Exp. conn pin #45
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A1 - |05 36| - /OE for stick #1
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A2 - |06 35| - /OE for stick #2
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A3 - |07 34| - /NMI
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A4 - |08 33| - R/W
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A5 - |09 32| - /IRQ
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A6 - |10 31| - M2
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A7 - |11 30| - GND (Abort?)
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A8 - |12 29| - 21.47727Mhz CLK
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A9 - |13 28| - D0
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A10 - |14 27| - D1
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A11 - |15 26| - D2
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A12 - |16 25| - D3
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A13 - |17 24| - D4
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A14 - |18 23| - D5
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A15 - |19 22| - D6
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GND - |20 21| - D7
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`----------'
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CPU
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