GP32 Porting Source Code


steven84

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hi people im just wondering how easy to do porting is? because ive found some open source sega mega drive emulators online and im wondering would these ones work any better than the egsisting ones?....


Steve :)

Edit:- damn its all in ASM which i dout can be ported :(
 

jlebrech

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Even porting from gp32 to gp32 is complicated, like converting something made with ads to the mirko lib.
 

SvOlli

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steven84 posted on Sep 11 2004 at 12:26 AM said:
hi people im just wondering how easy to do porting is? because ive found some open source sega mega drive emulators online and im wondering would these ones work any better than the egsisting ones?....
It'll involve a fair amount of work. I ported Stella (Atari 2600 VCS emulator) to the Dreamcast. To see it was possible (just to see a game intro running) took me a complete weekend. The first alpha release took me several weeks, since everything else beside emulation needed to be recoded (original Stella gets the name of the rom by command line, so a rom menu was needed.)
...continued... said:
Edit:- damn its all in ASM which i dout can be ported :(
Yup. That's right, porting asm is much like recoding the whole stuff, especially if it involves x86 code. Rest assured that someone who releases a port of something usually chose the original code for some serious reasons, like portabilty, speed of the original, etc. At least, just for putting some hard work down the drain. Like I chose not to port Stella to GP32, because it will always be running too slow.

Greetings.
SvOlli
 
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Squidge

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Porting an application written entirely in C is not normally that difficult as long as the program was meant to be portable. Idealy you want a program which uses functions to access the "outside world". Eg. it calls a function to update the display, get the joystick info, etc.

Programs that check hardware dependant things in several places throughout the code can be a complete bitch.

Plus don't forget many things, once ported, will need some level of optimising before they are usable. Take a look at BOR for example - the game worked, but many levels after the first (and MODs) failed because of lack of memory. I worked out how the sprite routines worked and rewrote them with saving memory in mind, and now look at it :)
 
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