oompa loompa
I AM THE GOVERNATOR
"Git 'Er Dun!"
Posts: 1,301
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Post by oompa loompa on Mar 3, 2004 0:31:27 GMT -5
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Fonzie
Moldy Popcorn
h?h
Posts: 31
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Post by Fonzie on Mar 13, 2004 19:57:55 GMT -5
Cool, Thats impressive for a basic-programmed game. Youre basic compilator seems to be complete...
Just a question.
Is it possible to compile a md game (128ko) for run from the scd ram? (The scd ram would remplace the cartridge).
If yes, what is the maximal lenght of direct acces from the genny without any bankswitch method?
Thanks
Fonzie
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oompa loompa
I AM THE GOVERNATOR
"Git 'Er Dun!"
Posts: 1,301
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Post by oompa loompa on Mar 16, 2004 13:34:57 GMT -5
do u mean compiling a basic program from the compiler to make a sega cd iso?
if yes =), then the maximum size of the compiled machine code has to be less than 128k, or else things will start glitching out. the compiler doesn't detect whether it has reached the limit. the program is run from the word ram at 0x200000
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Fonzie
Moldy Popcorn
h?h
Posts: 31
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Post by Fonzie on Mar 17, 2004 2:41:30 GMT -5
the compiler doesn't detect whether it has reached the limit ??
I am actualy dev. as sega genesis game (with sgcc). Whith music, the game is 1400ko lenght (damned gym). Without music, the games is 256k...
So youre telling me that the 128ko limit is just a compiler limit? I was thinking that this limit was a hardware limit (the genny was only able to acces 128k of the SCD ram at once).
Thanks for answer
Fonzie
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oompa loompa
I AM THE GOVERNATOR
"Git 'Er Dun!"
Posts: 1,301
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Post by oompa loompa on Mar 17, 2004 3:18:32 GMT -5
no it doesn't detect whether it has reached the limit. i could make it detect it, but its not one of my concerns right now for the vb version of the compiler (128k binaries would take a lot of code, and for the time it takes to compile all that code, its not worth it).
for your game, don't use gym x.x a whole meg for sound is huge. i'm making a format for playing music for the ym2612. i dunno what its gonna be like, haven't started it =D
the 128k limit is just basiegaxorz's limit. hardware wise, you have many many options. on the main cpu, you have the program ram (512k, banked 128k), work ram (256k), and your work ram (64k). the reason the compiler has the 128k limit is b/c the sega cd bios can only load a max of 128k for the boot sector. if i were to make a routine on the sub cpu that loads sectors so the main cpu could run them, then that would surpass the 128k limit to 256k. (basic compiled programs run in word ram)
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Fonzie
Moldy Popcorn
h?h
Posts: 31
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Post by Fonzie on Mar 17, 2004 13:16:10 GMT -5
Thanks,
So, the genny can acces to 256k(up to 512k) from the scd ram without any hardware limitations. Thats cool. But, if the genny use a part of the scd ram, the scd CPU is halted, isn't it?
Thanks.
I was using gym files because i don't want to spend lot of time on creating music and i haven't found any (good) midi player (tomie xie worked on it but, not for z80).
Ha, yes. Just a question: I was thinking that basic wasn't a compiled langage. How work youre basic compilateur: It just put the basic emulator+basic file on a binary? Or realy compile the basic onto a 68k asm?
Bye
Fonzie
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oompa loompa
I AM THE GOVERNATOR
"Git 'Er Dun!"
Posts: 1,301
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Post by oompa loompa on Mar 17, 2004 22:15:49 GMT -5
the slave cpu isn't halted, unless you want to halt it =D, just by settting a register. when the main cpu has permission to access ram that is shared by both the master and slave cpu, the memory is just disconnected from the slave's bus, and placed onto the master's bus, so no cpu halting needed =P
and to answer yer question, the basic compiler compiles basic to 68k code
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