The Expansion pak was a peripheral for the Nintendo 64 games console which provided an extra 4 Megabytes of RAM on top of the 4 that the N64 base unit carries. The pak was a small piece of black plastic with a red panel on top and it came with a jumper pak removal tool. This tool was shockingly enough used to remove the Jumper pak from the expansion slot. The jumper pak, as far as I know, has no real hardware in it except a circuit which allows the electrical signals to flow through - it is simply to fill the expansion gap until you bought an expansion pak. One you had removed the sticker (which said, menacingly enough, DO NOT REMOVE THIS STICKER, you inserted the jumper pak removal tool and pushed, and if you had done it right, the Jumper pak came out. You then slotted the expansion pak in and closed the cover. You are not supposed to remove the expansion pak ever - if a game does not take advantage of it then it will still work fine. I'm not sure if there is anything you can do with the jumper pak, but I've still got mine. If you had done it wrong, then the jumper pak tool would break. Idiot.

While the pak was originally conceieved as a design for use with the ill-fated 64DD add on, since that didn't see the light of day until 1999, (and even then it was only in Japan) the expansion pak was released as soon as it was ready and there was a game to take advantage of it. That first game was Turok 2: Seeds of Evil - although the game was frequently quite annoying in it's lack of save points, and huge levels which took forever to trek round, it did utilise the expansion pak to cause lovely high resolution visuals, meaning that it was appreciated in it's own way. This early attempt to use the extra power generally made the game run like a slideshow whenever anything interesting happened, programming improved and so did the games. Some notable games to use the expansion pak were:

Donkey Kong 64
The pak was required to run this at all. It used the pak to provide pleasing medium resolution visuals and coloured lighting. Unfortunately there was a whole fiasco about the pak being bundled with the game - see below.
Perfect Dark
Without the pak only the two player multiplayer and combat challenges were available. Installing a pak allowed the single player missions and up to four person multiplayer to be unlocked.
The Legend of Zelda: Majora's Mask
This game required the pak to run at all, but thankfully no bundling in fiasco occurred. THE Games had learned their lesson.
Turok 3: Shadow of Oblivion
Acclaim managed to solve the framerate probelms for their third Turok effort, but unfortunately gameplay suffered, an it was unviersally renowned as "not as good as Perfect Dark".

The Donkey Kong 64 problems came about when the game was released (a good year or so after the pak first came out) and Nintendo's UK distributors THE Games said that they would put a pak in with every copy of DK64. Naturally, people who had already bought a pak for use with another game were mightily annoyed, but the complaints fell on deaf ears. Eventually, The Big N took notice and (apparently) offered a free game from a selection for every unused expansion pak which was sent in. This disagreement between Nintendo and THE Games is probably what led to Nintendo dropping them a few years ago and installing a dedicated UK office. As far as I know, all this trouble did not happen in the US.

If you own an N64 and see a pak in a store, it is well worth your while buying it, if only so that you can play Perfect Dark and Majora's Mask. And as for exactly why there is no "C" in "pak", I have no idea*. I'm guessing it's a Nintendo thing. See also: Game Pak, Controller Pak, Rumble Pak, Jumper Pak.


Noder Comments:

dokool says IIRC, the Star Wars game Rogue Squadron also required the Pak.

Servo5678 has informed me that "As for buying a pak seperately in a store, I found it to be a better deal (circa late 2000) to buy DK64 for $40 and get a free pak rather than buying a pak on its own for $30."

Servo5678 also says "Mario Artist relied on the pak in some manner aside from the usual 64DDness. I'm trying to find out what's so special about it."


* - Someone has suggested that Nintendo name all their objects as pak without the c because it gives them a more trademarkable name, and "pack" would be too generic. This is just idle speculation though...


UPDATE!! Servo5678 has finally laid to rest the whole "Pak" issue with his writeup in Game Pak.