UltraHLE

Infobox_Software
name = UltraHLE


caption = UltraHLE 1.0.0 with some games found.
developer = RealityMan and Epsilon
latest_release_version = 1.0.0
latest_release_date = January 28, 1999
operating_system = Microsoft Windows
genre = Emulator
license = Freeware
website = [http://www.ultrahle.com/ www.ultrahle.com]

UltraHLE is an emulator allowing games for the Nintendo 64 game console to be run on a computer. It was hailed as a massive step forward in emulation technology upon its release in 1999. Emulating the N64 (which at the time was only 3 years old), it was the first of the N64 emulators to run commercial titles at a playable frame rate on the hardware of the time.

The HLE technique

Earlier emulators had concentrated on accurately emulating all of the low level operations which the target machine was capable of. It had worked well for older consoles such as the Super Nintendo and Sega Genesis.

Co-authors "Epsilon" and "RealityMan" realized that since N64 games were programmed in C code, that instead of intercepting machine level operations, they could concentrate on intercepting (the far fewer) C library calls, and write their own code to implement the libraries. Thus UltraHLE software is in fact an emulator with some parts implemented as a simulation. The HLE approach is therefore not a 100% emulator and the technique is not used in purist emulation projects such as MAME. It did however open the doors to create playable game emulators which use complex graphic routines that require considerable computation power that could be simulated easily with available PC graphic cards.

The final implementation was written in C and used the Glide API, which has since fallen out of use due to being specific to 3dfx adapters. Due to its popularity, several Glide to DirectX translating utilities were made specifically for UltraHLE for non-3dfx video cards.

High-level emulation had its drawbacks. At the time of release, UltraHLE was only able to emulate approximately 20 games to a playable standard. The software only emulated and simulated the calls that were required for specific games; it was required to adapt the software for games that used different parts of the N64 hardware.

The demise of UltraHLE

Also notable for its time, UltraHLE was capable of playing commercial games while the console was still commercially viable. Concerned about potential piracy, Nintendo threatened the authors and the site hosting UltraHLE, EmuUnlim, with legal action. Despite this, UltraHLE had grown beyond either its authors' or Nintendo's control. Subsequently "Epsilon" and "RealityMan" abandoned their pseudonyms and went into hiding.

After the source code was leaked in 2002, an OpenGL version of UltraHLE (UltraHLE 2064) was released, though it garnered little acclaim as several more powerful emulators had subsequently been released. UltraHLE 2064 was available at its official site until the site was deregistered.

External links

* [http://www.ultrahle.com ultrahle.com]
* [http://www.emuunlim.com/UltraHLE UltraHLE site]
* [http://ngemu.com/n64/uhle2064.php NGEmu UltraHLE 2064 Article]