Mainboard Revisions (NTSC)

PCB revisions run from NES-CPU-01 to -11.  Revisions below -05 will have noticeably poorer video output than later revisions.  Revisions -10 and -11 use circuitry to try to defeat the lockout defeaters of the unlicensed cartridges.

 

 NES-CPU-02 - 2A03E/2C02E-0 

 The original US release of the NES (fewer than 10,000 were made). 

 

 

 1985 copyright on PCB 

 VRAM and WRAM are NDIP-only 

 3193 Non-A CIC 

 

 

 NES-CPU-03 

 

 

 Unreleased 

 

 

 NES-CPU-04 - 2A03E/2C02E-0 

 

 

 1986 copyright on PCB 

 VRAM and WRAM are NDIP-only 

 3193 Non-A or 3193A CIC 

 some have a 74HC139 at U3 instead of 74LS139 

 

 

 NES-CPU-05 - 2A03G/2C02G-0 

 

 

 1986 copyright on PCB 

 VRAM and WRAM are NDIP-only 

 3193A CIC 

 

 

 NES-CPU-06 - 2A03G/2C02G-0 

 

 

 1987 copyright on PCB 

 VRAM and WRAM are NDIP or DIP 

 

 

 NES-CPU-07 - 2A03G/2C02G-0 

 

 

 1987 copyright on PCB 

 VRAM and WRAM are NDIP or DIP 

 

 

 NES-CPU-08 - 2A03G/2C02G-0 

 

 

 1989 copyright on PCB 

 VRAM and WRAM are NDIP or DIP 

 

 

 NES-CPU-09 - 2A03G/2C02G-0 or 2A07/2C07-0 

 

 

 1987 copyright on PCB 

 VRAM and WRAM are NDIP or DIP 

 

 

 Has one resistor between CIC pin and cart connector to prevent CIC stun attacks 

 NES-CPU-10 - 2A03G/2C02G 

 

 

 1987 copyright on PCB 

 VRAM and WRAM are NDIP or DIP 

 

 

 Has two resistors between CIC pins  and cart connector to thwart more CIC voltage stun, some later revisions have a diode to nearby GND vias as well to prevent the -5V attack 

 NES-CPU-11 - 2A03G/2C02G or 2A07[A]/2C07[A] 

 

 

 1987 Copyright on PCB 

 VRAM and WRAM are NDIP or DIP 

 

 

 Has two resistors and two diodes between CIC pins, cart connector and GND to prevent CIC stun and -5V attacks