PocketNES
PocketNES is a NES emulator which runs on the Game Boy Advance, written by Neal Tew (Loopy) and Fredrik Olsson (Flubba). It can run on a GBA through use of flash cartridges, or with the GBA Movie Player. The emulator has been released into the public domain, yet it remains under active development.
More than a year after the first release of PocketNES, Nintendo has re-released several of their NES games on the GBA through the e-Reader accessory, Animal Crossing GameCube game link feature, or Classic NES Series collection. Since PocketNES predates all of Nintendo's efforts, it is believed that PocketNES was the inspiration for Nintendo to create their own similar emulator.
NES gameplay issues
The GBA screen has a lower vertical and horizontal resolution than a NES's display. PocketNES compensates either by scaling the image down vertically, or by scrolling the image up or down. Such scrolling can either happen automatically, following the position of a sprite or value of a memory address, or manually using the GBA's L and R buttons. Sound is reproduced via the "classic" Game Boy PSG channels, rather than a software emulation of the NES's sound hardware; this is done to reduce CPU usage. As a result, it does not sound exactly like the original NES, although it is a close approximation.
Commercial use
PocketNES's source code is in the public domain. As a result, it has been used by game publishers and pirates alike. None of the companies have credited the original authors of the program, with exception of Konami in Contra 4.
Jaleco
Jaleco used PocketNES in Jajamaru Jr. Denshouki - Jaleco Memorial to emulate five of their Famicom games:
- Exerion
- Formation Z
- City Connection
- Ninja Jajamaru Kun
- Jajamaru no Dai Bouken
Atlus
Atlus used PocketNES in the Kunio kun Nekketsu Collection series to re-release Technos's Famicom titles on the GBA. They released three different volumes, each containing two games.
- Volume 1 contains SUPER Dodge Ball and Nekketsu! Street Basket - Ganbare Dunk Heroes.
- Volume 2 contains Downtown Nekketsu Kōshinkyoku: Soreyuke Daiundōkai and Nekketsu Koukou Dodgeball Bu - Soccer Hen.
- Volume 3 contains Downtown Special: Kunio-kun no Jidaigeki da yo Zen'in Shū;gō! and Ike Ike! Nekketsu Hockey-bu: Subette Koronde Dairantō (Crash 'n the Boys: Ice Challenge).
Hudson
Hudson Soft used PocketNES for their Hudson Best Collection series. There are six volumes available, each containing 2-4 games.
- Volume 1 contains Bomberman and Bomberman II.
- Volume 2 contains Lode Runner and Championship Lode Runner.
- Volume 3 contains Challenger and Milon's Secret Castle.
- Volume 4 contains Nuts and Milk, Binary Land, and Princess Tomato in the Salad Kingdom.
- Volume 5 contains Star Force, Star Soldier, and Hector'87.
- Volume 6 contains the four Adventure Island games.
Konami
The credits in Contra 4 thank the authors for the use of the "PocketNES Core". It was most likely used to emulate the original NES Contra and Super C found as bonuses within the game.
Bootleg use
PocketNES has also appeared without authorization on many bootleg GBA cartridges. Usually the pirate cartridges combine one or two Game Boy Advance titles with many pirated NES games to create multicarts.
Ports
PocketNES has been ported to Nintendo DS and is called nesDS
Patent issues
Nintendo filed for and was granted a patent on the vertical scaling method used in PocketNES in 2002, despite PocketNES's using it in 2001.