15

On each Motherboard of an NES-001 (NTSC) there is a code: NES-CPU-xx

These range from 04 to 11 (I think)

I would like to know if these are all of the revisions of the NES and what major differences there are between each one. (including chip sets, system architecture, etc) The most I can gather is that each revisions at least improves the CIC (10NES lockout security chip) but for even that I would love to know specifics. I have an 07. I will also be willing to accept pictures of other motherboards and share my own if possible.

3

Here are the differences that I've managed to dig up:

  • NES-CPU-02 - 2A03E/2C02E-0; 1985 copyright on PCB; VRAM and WRAM are NDIP-only; 3193 Non-A CIC; (This is the first one "released" in the USA, in the first 10,000? or so test release NES consoles, before wide release)
  • NES-CPU-03 - unclear if this was even shipped, haven't seen reports of it in the wild.
  • 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 (no other changes that I can see)
  • 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; (I can't see any electrical differences - these may be internal revision bumps?)
  • NES-CPU-08 - 2A03G/2C02G-0; 1989 copyright on PCB; VRAM and WRAM are NDIP or DIP. This is probably because of an issue with Roland MT-32 roms from 1986 which lost their copyright protection briefly in 1995/1996.
  • 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 (data?) and cart connector to thwart some 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 (clock and data?) and cart connector to thwart more CIC STUN attacks, some later pcbs have a hand-added-at-factory diode or diodes 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

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