If you’re an American in your early thirties, you probably have fond memories of playing Donkey Kong, Super Mario Bros., and The Legend of Zelda on a Nintendo Entertainment System. After the flameout of the Atari 2600 system, video gaming was in rough shape financially. The NES helped revitalize gaming and provided a strong template for future console makers to follow.

But the NES wasn’t the first of its breed. It was based on Nintendo’s Family Computer, aka the Famicom, released in Japan 25 years ago. Originally retailing for 14,800 yen (about $63.54 in 1983 dollars), the Famicom sparked a two-decade-long era of Japanese console dominance and sold 61.9 million units worldwide in its various forms.

Few westerners have seen the original unit that launched Nintendo’s video game empire, but that’s about to change. We’ll examine an original 1983 Famicom, its controllers, its games, and even a unique disk system accessory that never released outside of Japan.

(Benj Edwards is the founder and editor in chief of Vintage Computing and Gaming. He wrote the captions and produced the photos for this slide show. Other classic tech gear he’s torn down include the Apple IIc, the TRS-80 Model 100, and the World’s Greatest Keyboard.)

The Famicom system was designed by the R&D 2 team at Nintendo, led by engineer Masayuki Uemura. The console itself is simple and compact, measuring roughly 6 inches by 8 inches. You’ll notice three controls on the surface of the console: a power switch, a reset button, and a center lever that the user pushes forward to eject a cartridge. The unit even has a hinged flap to cover the cartridge port when not in use.

On the front edge of the unit is the Famicom’s accessory port, a 15-pin male connector (DA-15). This connector accommodates peripherals such as light guns, steering wheels, joysticks, and microphones.

To overcome the stigma associated with video games in the post-crash American market, Nintendo redesigned the Famicom to look more like an appliance or a VCR than a game console. The result was the Nintendo Entertainment System (1985), seen here underneath the Famicom. Nintendo was also cautious not to use the term “video game” in its NES marketing literature, calling the console an “Entertainment System” instead. In contrast, the toy-like Famicom was unabashedly designed with children in mind.

You could swap controllers for the NES, but the Famicom shipped with two control pads permanently wired into the console. The system even featured two molded slots where you could store the pads when you weren’t playing.

Famicom cartridges were generally constructed of two molded plastic halves that snapped together without screws. Inside is a printed circuit board with either discrete ROM packages or “glob-tops,” in which the silicon chips containing the game data are encased in a blob of resin.

Unlike the NES, the Famicom had no one standard cartridge design. Different game manufacturers crafted their own carts, some of which you can see here. The tan cartridge in the middle even contains an LED that lights up when the system is powered on.

The Famicom was the first video game console to use “control pads” as the main form of input. In contrast to the then-popular joystick, the control pad used a flat, cross-shaped thumb pad (often called a directional-pad or D-pad) that allowed for quick and accurate control. The design remains standard on most game controllers to this day.

You’ll notice that the second controller (marked ‘II’, right) lacks the start and select buttons of the first but features a built-in microphone and volume slider (more on that in a moment). This idiosyncracy of the Japanese system had some effects in the United States version. Early NES games such as Super Mario Bros. wouldn’t pause with a press of the second controller’s start button, because the Japanese counterpart had no equivalent button.

After disassembling Controller II, we see the main PC board and the two plastic halves of the controller case. All the surface controls are composed of hard plastic buttons that rest upon flexible rubber inserts (upper left) with conductive pads on them. When a player pushes a button, it collapses the rubber insert and the conductive pad completes a circuit on the green board seen here, registering the button press with the console.

Here’s the printed circuit board of Controller II up close. The microphone never appeared in NES control pads.

While the Famicom is on, the microphone relays any sound it picks up directly to the TV speaker. The Legend of Zelda used this feature in a novel way: It allowed the player to shout into the controller to kill a certain monster.

The silver strips to the left of the mic are part of the volume slider assembly, which controls the volume of the microphone output through the TV speaker.

Here’s the back of the Famicom. From left to right are the AC adapter port, a TV/Game switch (to turn off RF output for watching TV while the game continues to run), a channel-selector switch (for choosing which TV channel the game will display on), and the RF audio/video output that leads to the external RF switch (which, in turn, plugs into the antenna terminals on a TV set). On either side, you’ll notice two black cords protruding from the back of the console; those lead to the two built-in control pads.

Six screws later, we’re inside, and the bottom of the motherboard and the RF modulator/power-supply board are exposed. Two controller cords run down both sides of the upper chassis and plug into two connectors on the motherboard near the front of the unit. Controller II’s connector is slightly larger than Controller I’s because of the added microphone functionality.

The Famicom’s internal layout is quite spartan. One board contains an RF modulator for video output to the TV, and a power-supply circuit. The motherboard below contains the computerized brain of the Famicom, which we’ll examine in more detail soon.

To the right of those two boards is the upper half of the Famicom chassis. Near the center of that sits a large U-shaped piece of plastic connected to a spring, which is part of the cartridge ejection assembly. Below that are the plastic reset button (left) and the power switch (right), which connects to the power-supply board via two long red and white wires.

This board is the heart of the Famicom. A large, blue 60-pin connector at the top of the board connects to cartridges that plug into the system. The CPU is a modified 8-bit MOS 6502 microprocessor running at 1.79 MHz. The custom “picture processing unit” (PPU) generates the Famicom’s 256-by-224-pixel video image.

The two black ports on the front edge of the board connect to the control pads.

Released on February 21, 1986, the Famicom Disk System (FDS) was Nintendo’s first major attempt to circumvent the limitations of the Famicom’s hardware and extend the life of its already aging console.

Prior to the Disk System, the largest game cartridge contained 48 kilobytes of data, and larger ROM chips were prohibitively expensive. In contrast, the FDS provided up to 128K of storage space per disk. Later, as ROM prices dropped and disk piracy became rampant, the FDS lost relevance and faded into the background, although Nintendo supported it until 2003.

The FDS has two components: the RAM adapter (left) and the disk drive unit (right).

A Japanese Famicom game cartridge is quite small compared with the American NES cartridge to its left.

Official Nintendo “disk cards” were double-sided (64K per side), 2.8-inch proprietary floppy diskettes. They lacked a protective shutter, which caused many disks to fail when the internal magnetic media was exposed to dirt or accidentally touched.

The rewritable nature of the FDS disks allowed players to save game progress between sessions. Battery-backed SRAM in games such as The Legend of Zelda later replicated that functionality to a limited extent.

Lifting the top off of the disk drive housing exposes a battery compartment. Accessible from a door on the top of the unit, this compartment holds six C-cell batteries. The drive also accepts power from an AC adapter, but Nintendo included the battery option in case the Famicom and a TV set already occupied the nearest power outlet.

Below the battery compartment is the disk drive mechanism itself, which you’ll see more of in a moment.

Here I’ve removed the power-supply board (left) and the disk drive mechanism from the plastic disk drive unit housing.

Nintendo’s proprietary disk format was based on a similar (but smaller) floppy format called the “Quick Disk” that never gained a foothold in the computer industry–it was used mostly in 1980s music synthesizers. Mitsumi manufactured the FDS disk drives for Nintendo, including the unit you see here.

The Famicom Disk System had one major Achilles’ heel: a rubber drive belt, which often broke or melted into a pile of gunk with the consistency of bubble gum. As a result, finding a working FDS today that hasn’t had its drive belt replaced is impossible. Furthermore, finding replacement belts in the United States is also hard, due to the belt’s unique size.

As you can see in the picture, this unit is no exception. At some point the belt degraded, snapped, and wrapped around the motor drive shaft.

Here’s a peek inside the FDS “RAM adapter.” This device plugs into the cartridge port of the Famicom and provides the interface between the Famicom and the disk drive unit. Its cable connects to the back of the disk drive box.

The RAM adapter contains 32K RAM for temporary program storage (loaded from disk), 8K additional RAM for games to utilize, and a custom chip that includes extra sound hardware and a floppy-disk controller.

As seen here, the Family Computer connected neatly to the Famicom Disk System and still left room for the controllers to tuck snugly into the sides of the main Famicom unit.

Overall, the Famicom’s influence on the art and science of video games has been profound. But the Famicom’s greatest achievement was that it provided fun for millions of kids. And for that, we should all thank Nintendo for a job well done.

Happy 25th birthday, Family Computer.