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Two Japanese dumps today.

First we have a variation of Aerial Assault for the Game Gear (エアリアルアサルト). The code only include a minor change related to the game initialization process, and I believe is related to Game Gear with or without BIOS (someone in the forum will probably analyze this in more depth).

Second we have Garou Densetsu Special for the Game Gear (餓狼伝説スペシャル), Japanese version of Fatal Fury Special, as ported by Takara from its original NeoGeo version. Graphics were scaled in a way that looking close at them they appear awful, but in the end the original animation key frames are respected with good detail.

See you soon for more dumps!

As Bock mentioned, the change is indeed very minor. The "version 0" code is doing some startup operations (setting paging registers, clearing RAM) before setting the stack pointer. Before this point in the code, there is a possibility that it could be interrupted by a signal on the Gear-to-Gear cable; if this happened, it would try to use the stack which hasn't been initialised (and thus has the default value of $0000). The effect would be that it would write the return address to the paging registers and thus overwrite the initialisation just performed. The "version 1" code instead sets the stack pointer before, instead of after, this part of the initialisation, and thus avoids the problem.

On a Game Gear with a "BIOS" (showing "Produced by or under license from Sega Enterprises Ltd."), the stack pointer is already set to a suitable value, so it isn't a problem.

Author	Message
Bock Site Admin Joined: 08 Jul 2001 Posts: 8648 Location: Paris, France	Aerial Assault [v1] (GG/JP), Garou Densetsu Special (GG/JP) Posted: Sun May 25, 2008 6:07 pm
	Two Japanese dumps today. First we have a variation of Aerial Assault for the Game Gear (エアリアルアサルト). The code only include a minor change related to the game initialization process, and I believe is related to Game Gear with or without BIOS (someone in the forum will probably analyze this in more depth). Second we have Garou Densetsu Special for the Game Gear (餓狼伝説スペシャル), Japanese version of Fatal Fury Special, as ported by Takara from its original NeoGeo version. Graphics were scaled in a way that looking close at them they appear awful, but in the end the original animation key frames are respected with good detail. See you soon for more dumps!

Maxim Site Admin Joined: 19 Oct 1999 Posts: 14733 Location: London	Posted: Mon Jun 09, 2008 1:35 pm
	As Bock mentioned, the change is indeed very minor. The "version 0" code is doing some startup operations (setting paging registers, clearing RAM) before setting the stack pointer. Before this point in the code, there is a possibility that it could be interrupted by a signal on the Gear-to-Gear cable; if this happened, it would try to use the stack which hasn't been initialised (and thus has the default value of $0000). The effect would be that it would write the return address to the paging registers and thus overwrite the initialisation just performed. The "version 1" code instead sets the stack pointer before, instead of after, this part of the initialisation, and thus avoids the problem. On a Game Gear with a "BIOS" (showing "Produced by or under license from Sega Enterprises Ltd."), the stack pointer is already set to a suitable value, so it isn't a problem.

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View topic - Aerial Assault [v1] (GG/JP), Garou Densetsu Special (GG/JP)