Nintendo NES gamecomputer

Nintendo nes Nintendo's origins date back to 1889 with the making of playing cards, where they became quite big. In 1963 they also started making games in addition to playing cards. In 1970, Nintendo stopped mnaking playing cards and by then they focused on making toys. In July 1983 they released their first own game console, the Famicom with games like Donkey Kong, Donkey Kong Jr and Popeye as launch titles. By the end of the year the Famicom's game collection consisted of a lot of games including Mario Bros. Nintendo didn't have any third-party software developers and sold over a million Famicom systems, proving the powerb of their own software. Nintendo decided in 1985 that it was necessary to adjust the design of the Famicom. The console took the form of a simple box with two controller ports and a slot to insert the game cartridge. The game console was renamed to Nintendo Entertainment System (NES). The original NES package, which was released as a test in New York City during the fall of 1985, contained two controllers, an adapter and cables to connect it to the television. Super Mario Bros became a big hit, selling a million copies. Read more about the history of Nintendo!

The Nintendo NES was also the first real game console we bought for my kids and we spent hours watching our oldest son playing Super Mario on the Nintendo NES on the living room television set. Since I have an electrical engineering background, the first adjustment (undoing the region code) quickly done and knew what was inside the Nintendo NES. One of my sons has another Nintendo NES and even my youngest daughter also enjoyed the games. I think it's partly because the graphic possibilities weren't that great, the makers had to make sure the game was super well put together. Nowadays I often notice that the quality of the graphics is great but that this has come at the expense of the story and the game line. Since the Nintendo NES hardware was fairly simple, there are quite a few emulators and Nintendo NES games can be played on almost any platform. A few years ago I made Nintendo NES case console by means of a Raspberry Pi a complete with hundreds of games on board. This page is about the Nintendo NES and everything I've collected about this over the past few years. Kind regards, Hein Pragt.

Specificaties van Nintendo NES spelcomputer

  • CPU type: modified 6502 8-bit (NMOS)
  • CPU speed: 1.79 Mhz
  • RAM memory: 16 Kbit (2 Kbyte)
  • Video RAM: 16 Kbit (2 Kbyte)
  • Picture resolution: 256x240 pixels
  • Colors Available: 52 colors
  • Max colors at once: 24 colors
  • Max sprite size: 8x16 pixels
  • Max sprites: 64 sprites
  • Min/Max Cart Size: 128 Kbit - 4 Mbit
  • Max sprites per Scanline: 8 sprites
  • Sound: PSG sound

The NES CPU was a (customized) 6502 8-bit (NMOS) processor at 1.79 Mhz, this was a dedicated chip, but nowedays you can buy this custom chip in China. The internal memory consisted of 2 Kbytes of ram and the system also had 2 Kbytes of video ram. The video resolution is 256 x 240 pixels with a total of 52 colors of which 24 can be used simultaneously. The sprite engine supported a maximum of 64 sprites with a resolution of 8 x 16 pixels. The maximum size of a cartridge was 4 megabits. The NES also had its own sound chip with which the typical NES sound was made. Who does not know the typical sounds of the Mario game.

Electronics schematics of the NES

Here are the electronics schematics of the NES console, on the page they are reduced displayed, when you save these electronics schematics on your own computer by means of the right mouse button you will download them in large format.

Schema deel 1

schema's NES

Schema deel 2

schema's NES

Schema deel 3

schema's NES

Schema deel 4

schema's NES


Information about the Catridge pinout

NES roms pinout.

NES MASK ROM Pinouts:
---------------------------------------------
PRG ROM - 32KBytes (28pin): 
(no need to change any pins on EPROM)

                  ---_---
       +5V     - |01   28| - +5V
       PRG A12 - |02   27| - PRG A14
       PRG A7  - |03   26| - PRG A13
       PRG A6  - |04   25| - PRG A8
       PRG A5  - |05   24| - PRG A9
       PRG A4  - |06   23| - PRG A11
       PRG A3  - |07   22| - PRG /CE
       PRG A2  - |08   21| - PRG A10
       PRG A1  - |09   20| - GND
       PRG A0  - |10   19| - PRG D7
       PRG D0  - |11   18| - PRG D6
       PRG D1  - |12   17| - PRG D5
       PRG D2  - |13   16| - PRG D4
       GND     - |14   15| - PRG D3
                  -------

---------------------------------------------
PRG ROM - 128KBytes (28pin):
 
                  ---_---
       PRG A15 - |01   28| - +5V
       PRG A12 - |02   27| - PRG A14
       PRG A7  - |03   26| - PRG A13
       PRG A6  - |04   25| - PRG A8
       PRG A5  - |05   24| - PRG A9
       PRG A4  - |06   23| - PRG A11
       PRG A3  - |07   22| - PRG A16
       PRG A2  - |08   21| - PRG A10
       PRG A1  - |09   20| - PRG /CE
       PRG A0  - |10   19| - PRG D7
       PRG D0  - |11   18| - PRG D6
       PRG D1  - |12   17| - PRG D5
       PRG D2  - |13   16| - PRG D4
       GND     - |14   15| - PRG D3
                  -------

----------------------------------------------
PRG ROM - 256KBytes (32pin):

                  ---_---
       PRG A17 - |01   32| - +5V
       PRG /CE - |02   31| - +5V
       PRG A15 - |03   30| - +5V
       PRG A12 - |04   29| - PRG A14
       PRG A7  - |05   28| - PRG A13
       PRG A6  - |06   27| - PRG A8 
       PRG A5  - |07   26| - PRG A9
       PRG A4  - |08   25| - PRG A11
       PRG A3  - |09   24| - PRG A16
       PRG A2  - |10   23| - PRG A10
       PRG A1  - |11   22| - PRG /CE
       PRG A0  - |12   21| - PRG D7
       PRG D0  - |13   20| - PRG D6
       PRG D1  - |14   19| - PRG D5
       PRG D2  - |15   18| - PRG D4
       GND     - |16   17| - PRG D3
                  -------

(note: pins 2 and 22 are connected together on the PCB)

----------------------------------------------
PRG ROM - 512KBytes (32pin):

                  ---_---
       PRG A17 - |01   32| - +5V
       PRG A18 - |02   31| - +5V
       PRG A15 - |03   30| - +5V
       PRG A12 - |04   29| - PRG A14
       PRG A7  - |05   28| - PRG A13
       PRG A6  - |06   27| - PRG A8 
       PRG A5  - |07   26| - PRG A9
       PRG A4  - |08   25| - PRG A11
       PRG A3  - |09   24| - PRG A16
       PRG A2  - |10   23| - PRG A10
       PRG A1  - |11   22| - PRG /CE
       PRG A0  - |12   21| - PRG D7
       PRG D0  - |13   20| - PRG D6
       PRG D1  - |14   19| - PRG D5
       PRG D2  - |15   18| - PRG D4
       GND     - |16   17| - PRG D3
                  -------

---------------------------------------------
CHR ROM - 32KBytes (28pin):
(no need to change any pins on EPROM)
 
                  ---_---
       +5V     - |01   28| - +5V
       CHR A12 - |02   27| - PRG A14
       CHR A7  - |03   26| - PRG A13
       CHR A6  - |04   25| - CHR A8
       CHR A5  - |05   24| - CHR A9
       CHR A4  - |06   23| - CHR A11
       CHR A3  - |07   22| - CHR /RD  (OE)
       CHR A2  - |08   21| - CHR A10
       CHR A1  - |09   20| - CHR /A13 (CE)
       CHR A0  - |10   19| - CHR D7
       CHR D0  - |11   18| - CHR D6
       CHR D1  - |12   17| - CHR D5
       CHR D2  - |13   16| - CHR D4
       GND     - |14   15| - CHR D3
                  -------

----------------------------------------------
CHR ROM - 128KBytes (32pin):

                  ---_---
       +5V     - |01   32| - +5V
  (OE) CHR /RD - |02   31| - CHR /A13 (CE)
       CHR A15 - |03   30| - +5V
       CHR A12 - |04   29| - CHR A14
       CHR A7  - |05   28| - CHR A13
       CHR A6  - |06   27| - CHR A8 
       CHR A5  - |07   26| - CHR A9
       CHR A4  - |08   25| - CHR A11
       CHR A3  - |09   24| - CHR A16
       CHR A2  - |10   23| - CHR A10
       CHR A1  - |11   22| - GND
       CHR A0  - |12   21| - CHR D7
       CHR D0  - |13   20| - CHR D6
       CHR D1  - |14   19| - CHR D5
       CHR D2  - |15   18| - CHR D4
       GND     - |16   17| - CHR D3
                  -------

----------------------------------------------
CHR ROM - 256KBytes (32pin):

                  ---_---
       CHR A17 - |01   32| - +5V
  (OE) CHR /RD - |02   31| - CHR /A13 (CE)
       CHR A15 - |03   30| - +5V
       CHR A12 - |04   29| - CHR A14
       CHR A7  - |05   28| - CHR A13
       CHR A6  - |06   27| - CHR A8 
       CHR A5  - |07   26| - CHR A9
       CHR A4  - |08   25| - CHR A11
       CHR A3  - |09   24| - CHR A16
       CHR A2  - |10   23| - CHR A10
       CHR A1  - |11   22| - GND
       CHR A0  - |12   21| - CHR D7
       CHR D0  - |13   20| - CHR D6
       CHR D1  - |14   19| - CHR D5
       CHR D2  - |15   18| - CHR D4
       GND     - |16   17| - CHR D3
                  -------

----------------------------------------------
WRAM - 8KBytes (28pin):

                  ---_---
       +5V     - |01   28| - +5V
       PRG A12 - |02   27| - WRAM /WE
       PRG A7  - |03   26| - WRAM /CE
       PRG A6  - |04   25| - PRG A8
       PRG A5  - |05   24| - PRG A9
       PRG A4  - |06   23| - PRG A11
       PRG A3  - |07   22| - GND
       PRG A2  - |08   21| - PRG A10
       PRG A1  - |09   20| - WRAM /CE
       PRG A0  - |10   19| - PRG D7
       PRG D0  - |11   18| - PRG D6
       PRG D1  - |12   17| - PRG D5
       PRG D2  - |13   16| - PRG D4
       GND     - |14   15| - PRG D3
                  -------

Additional (English) information about the roms and the memory mapper.

Catridge pinout and mappers pinout rom.txt

Nintendo's MMC1 mapper informatie mmc1.txt


Description how to disable the "lockout chip" on the NES.

uitschakelen kopieerbeveiliging NES When nintendo designed the Nes they put a so-called lockout chip in to make sure that only licensed companies could release games for the NES and they could also use region codes so that USA cartridges would not work on European NES systems. It worked like this, the lockout chip was in the console as well as the cartridge and when the NES was turned on, the chip from the console will communicate with the chip in the cartridge. If the codes did not match, the chip would reset the NES every second. However simply cutting one pin of the chip could undo this protection.

(Download 'Disabling the NES Lockout Chip', by Mark Knibbs)

Last update: 11-05-2022


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