oompa loompa
I AM THE GOVERNATOR
"Git 'Er Dun!"
Posts: 1,301
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Post by oompa loompa on Nov 27, 2004 22:34:37 GMT -5
oh yes, since it is thanksgiving, i'm giving "thanks" to all my "precious" users by releasing 2 more cool 32x demos: devster.retrodev.com/sega/32x/devstertest11.zipdevster.retrodev.com/sega/32x/devstertest12.zipthere's more on my sega page. it goes all the way up to 21, but its mostly the same demo with just little tweaks the first one shows an xor pattern the second one rotates the pattern around and scales it and etc. it is very very slow! it makes the 32x look like the images was drawn on the 68k =). i need to learn more about the crappy sh2 cache, and find ways to disable things from stealing my precious cycles >.<. i'll see if i can use the slave sh2 for this, but i doubt it'll make it faster, unless i split the image in 2 for both cpu's to process parallel to each other
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Post by Fonziev on Nov 29, 2004 8:09:34 GMT -5
Wow tons of demos !!!
Ummm. Since you're writing all in ASM sh2, i suppose that its slow because you don't use a "good" method for rotate and zoom... Maybe you should ask SteeveSnake (?) or somebody very good @ 2D manipulations to get some infamous software tips.
There is also another factor, youre working on a 320*224 picture, lol. Games like knuckels chaotix or cosmic carnage are working on lighter things (32*32?).
I have some game ideas using some very very gorgerous scalled sprites (gorgerous like after burner ^^)... Using the mainSH2 to do some game engine calculation, the sub-sh2 as a VDP (for massive sprites) and the genesis CPU as a VDP (for road) and joypad check / music play. Youre work is very exiting!
Bye
Fonzie
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Post by GiGaBiTe on Dec 5, 2004 2:46:12 GMT -5
if you double the clock rate of both sh2's your rotating checkerboard demo runs very nice.
reg sh2 speed = 23.5 MHz
overclocked sh2 speed = 47 MHz
just make sure you have some big heatsinks on both of the cpus or they will melt.
overclocked sh2's also make some other games run more smoothly (ex. darxide)
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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 Dec 6, 2004 16:03:53 GMT -5
wow, didn't know you could overclock the sh2's
there might be a way to do it in software too that will select a multiplier for the pll, like for a cypress arm processor i use
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Post by GiGaBiTe on Dec 8, 2004 3:02:37 GMT -5
i fiddled with a 32x and first you have to determine which sh2 the game uses to render the screen and which it uses to execute game code. i used the gens emulator to figure that out.
darxide uses the master sh2 for game code and the slave for screen rendering, so its better if you double the clock rate of the second sh2.
i find that darxide runs better with these cpu speeds
master sh2 = 23.5 MHz slave sh2 = 47 MHz
i tried other cpu speeds on the emulator, but 47 MHz only seemed to work on the hardware. if you pump both up it just plays uber fast.
if you make the cpus run over 47 MHz, the unit becomes unstable (and heat is a big issue) the genesis cant communicate with the 32x properly anymore and the game will usually lock up.
but if it doesnt, the game is pretty much unplayable, the controls are way too fast and the game is rendered way too fast. also the sound get really choppy.
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oompa loompa
I AM THE GOVERNATOR
"Git 'Er Dun!"
Posts: 1,301
|
Post by oompa loompa on Dec 8, 2004 23:01:27 GMT -5
hehe, very nice work =D
the controllers cannot be read by any of the sh2's, the genesis needs to read them, and then send information about them to the sh2 using communications ram. i guess controls go super fast is because the games rely on their own lag =P
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Post by GiGaBiTe on Dec 24, 2004 20:29:07 GMT -5
i tested other games with both sh2s @ 47 MHz, and got different results. some played erraticaly and some when were loaded down normally didnt slow down at all. knuckles chaotix worked better with the sh2s clock doubled and other game just locked up or started bugging out. i also did some internet reasearch and found a couple of sites that had the 32x sh2s info. now either sega requested some custom sh2s or they changed the clock on them. the sh2s in the 32x were originally meant for 28.7 MHz, not 23.5 MHz i cant remember the exact number on the sh2 chip, but its something like HDxxx70xx , you can find the pinouts here: america.renesas.com/servlet/requestinteresting because the sega saturn uses i think the exact same hitachi cpus. 32x = saturn without the clockwork?
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oompa loompa
I AM THE GOVERNATOR
"Git 'Er Dun!"
Posts: 1,301
|
Post by oompa loompa on Dec 26, 2004 13:55:35 GMT -5
devster.retrodev.com/pics/p2010072.jpgthey weren't custom cpu's, they had an "off-the-shelf" part number. i dunno why sega chose 23mhz as the stock speed, maybe it has something to do with the slowdown of 68k hardware
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Post by GiGaBiTe on Dec 27, 2004 23:15:53 GMT -5
maybe you could disconnect the 2 clock pins and generate your own frequency to make them run at standard speed. but id imagine with pins that small surface mounted on the board would be extremely hard to do that.. id think the best and most likely the hardest way to make them run faster would be to physically remove both sh2s and go get some faster sh2s from the same family, then put a variable switch on both of them (or most likely make one switch that controled both so they wouldnt go out of sync) that way you could develop some cool stuff without hardware speed limits. such as that open3d engine thing. if i were to try something like that i would try to use a SH7054 (40 MHz) because it has the least pins out of the group, less to do to make a converter
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