CPU pinout

Pinout
^                                               / \                                               /   \                                              /     \                                      +5V -- / 1 100 \ -> CPU A7                                  CPU A8 <- / 2    99 \ -> CPU A6                                 CPU A9 <- / 3. 98 \ -> CPU A5                              CPU A10 <- / 4        97 \ -> CPU A4                              CPU A11 <- / 5          96 \ -> CPU A3                             CPU A12 <- / 6            95 \ -> CPU A2                            CPU A13 <- / 7              94 \ -> CPU A1                           CPU A14 <- / 8                93 \ -> CPU A0                          CPU A15 <- / 9                  92 \ -> CPU /RD CPU A16 <- / 10                  91 \ -> CPU /WR CPU A17 <- / 11                    90 \ -- GND CPU A18 <- / 12                      89 \ -> /VECTORPULL CPU A19 <- / 13                        88 \ -> UNKNOWN CLK 88 CPU A20 <- / 14                          87 \ -> VDA CPU A21 <- / 15                            86 \ -> VPA CPU A22 <- / 16                              85 \ -- +5V A23 <- / 17                                84 \ -> XFLAG GND -- / 18                                  83 \ -> MFLAG joypad IO D0 <> / 19                                    82 \ -> /MEMLOCK joypad IO D1 <> / 20                                      81 \ <- RDY joypad IO D2 <> / 21                                           \ joypad IO D3 <> / 22                                    O       / joypad IO D4 <> / 23                                         80 / -> R/W joypad IO D5 <> / 24                                         79 / -- GND joypad IO D6 <> / 25                                         78 / -> /WRAMSEL joypad IO D7 <> / 26             Nintendo 5A22               77 / -> /ROMSEL joypad 2 D0 -> / 27     Package QFP-100, 0.65mm pitch       76 / <- /ABORT joypad 2 D1 -> / 28                                         75 / <- HALT joypad 2 D2 -> / 29                 S-CPU                   74 / <- HVCMODE joypad 2 D3 -> / 30                                         73 / <- TM               /       O                                     72 / -> PHI2 \                                           71 / -> UNKNOWN CLK 71 joypad 2 D4 -> \ 31                                      70 / -> /DMA joypad 1 D0 -> \ 32                                    69 / -> /PWR joypad 1 D1 -> \ 33                                  68 / -> /PRD +5V -- \ 34                                67 / <> CPU D7    joypad 1 /OE <- \ 35                               66 / <> CPU D6     joypad 2 /OE <- \ 36                             65 / <> CPU D5              OUT0 <- \ 37                           64 / <> CPU D4                 Orientation: OUT1 <- \ 38                        63 / <> CPU D3                                  OUT2 <- \ 39                       62 / <> CPU D2                       80         51 REFRESH <- \ 40                    61 / <> CPU D1                         |         | TCKSEL0 -> \ 41                  60 / <> CPU D0                         .---. TCKSEL1 -> \ 42                59 / -- +5V                          81-|O Nintendo |-50 HBLANK -> \ 43              58 / -> PA7                              |   S-CPU   | VBLANK -> \ 44            57 / -> PA6                           100-|. 5A22 O|-31 /NMI -> \ 45          56 / -> PA5                                .---' /IRQ -> \ 46        55 / -> PA4                                  |         | GND -- \ 47      54 / -> PA3                                  01         30 SYSTEM CLK -> \ 48    53 / -> PA2 REFRESH /ENABLE -> \ 49  52 / -> PA1                      Legend: /RESET -> \ 50 51 / -> PA0 \    /                               --[5A22]-- Power, n/a \  /                                ->[5A22]<- 5A22 input \ /                                <-[5A22]-> 5A22 output V                                 <>[5A22]<> Bidirectional

Signal descriptions

 * VPA, VDA: Valid Data Address and Valid Program Address, useful for caching or single-step.
 * VPA = 0, VDA = 0: Address bus may be invalid.
 * VPA = 0, VDA = 1: Valid data address
 * VPA = 1, VDA = 0: Valid program address
 * VPA = 1, VDA = 1: Opcode fetch