Gp2x Delfault Runing 298mhz !!!


Hehehe, im sure itll go straight onto gp32x.de as soon as Evildragon, or Hando sees it!
 
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god_at_hell posted on Dec 9 2005 at 03:53 PM said:
doh ... i yust didn't get, that new treads have to be approved by a higher being :D

now i posted TWO threads ... gna ...

Moo-Hahaha!

Man.. I sure do hope I get my Gp2x tommorrow [5-7days] [tommorrow is 7 :D ] I really wanna see how metal slug is ive never played it before heh and with this it runs superb with mp3!
 
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Just used the one in the file archive... That one definately works. :D
SNES without sounds is quite playable at 266 MHz! Almost fullspeed even. And without the 2nd CPU going, even more power efficient.

Thanks everyone who worked on that!
 
It seems that 266mhz isn't always stable (only got quake to complete a timedemo once, all other attempts fail after a little while), but 250mhz works well for me. Those lower speeds still need a bit of work though - the flicker is unbearable at 60 or 66mhz.
 
woogal posted on Dec 10 2005 at 12:00 AM said:
It seems that 266mhz isn't always stable (only got quake to complete a timedemo once, all other attempts fail after a little while), but 250mhz works well for me.

same, i noticed that sometimes it could even crash IMMEDIATELY when setting 266, even before to go back to the browser :D


it seems 266 is less stable than 280 :p (but 280 ended by crashing quake too anyway :D )


250 looks good :) and with NO flicker! B)

(edit: 250 just crashed after some minutes of SNES :p )
 
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To set up the LCD controller when the clock is changed, follow this procedure:

One horizontal scan line consists of 320 pixels, plus a HSync period of 84 clocks (by default) - that is 404 clocks.
One vertical scan consists of 240 horizontal lines + 22 VSync lines - that is 262 lines or 105,848 clocks.

To get a display refresh rate of 60Hz, we need the clock to be 60*105848 = 6350880 Hz, or around 6.35MHz.

The display clock is set by the DISPCSETREG register. In that, you can choose a clock source and a prescaler. By default, this is set to 0x4A00, which means the source is FPLL, and the prescaler divides by 11, to the default display clock is 199065600/11 = 18.096873MHz. That's almost exactly 3 times what I'd expect it to be, so if anyone can explain this mystery factor of 3, I'd really appreciate it!

Anyway, if you change FPLL, set DISPCSETREG to (0x4000 + (((fFPLL / 18100000)-1)<<8). That should make the display adjust correctly. For example, for 200MHz, this gets 0x4A00, which is correct. For 100MHz, set it to 0x4400, and for 60MHz, set it 0x4200 (these won't get exactly 60Hz).

Play around with this, you may get some interesting results :)
 
Could someone with a multimeter check how much more/less power is being used at different speeds?

And the flicker seems to go at higher speeds. Could it be that the original firmware ran at a higher clock speed? Could anyone with the original formware check their clock speed?
 
I tried tried the psx emulator at 2 speeds and tried FF7 and DOA. Playing them at 266mhz was a speed boost and is more playable now.

280mhz:
FF7 crashes early on, in the intro video.
DOA crashes a towards the end of the fight.

266mhz:
FF7 shows some good improvement speed wise.
DOA is a lot more playable than before(I actually had the patience to go through a round).
 
This is great. I would love to see someone integrate this code into their projects. eg. lower speed for puzzle games, choosable speeds for emus etc.
 
Maybe someone could get a version of this that loads on boot cause it really solves a lot of problems(at least in my gp2x :D).Perfectly stable(except for the video player which doesn't even start) with none of the previous,lcd related problems at 280.
 
The video player doesn't start because it uses the second CPU which this program turns off. I don't know why you'd want to clock higher to watch videos though. :blink:
 
how did you get DOA working, i have a ripped rom (says its an iso) and i got to the green screen for a long time and nada, how do i make it a bin or whatever?
 
An interesting "people fix" is to use this to clock at 60mhz.

The flickering is so bad that once you go back to 200mhz, any incidental flickering will barely bother you, now that you know what flickering really is.

Robster,

Are you able to make me a program to set the refresh to 100Hz?

I must do this on all my computers to stay sane, if I need to do this to my GP2X I would like a way to do it.
 
i can play divx movies ok, change the div setting to something other than 0 (i set it on div 1)i guess, still couldnt get that rom to work, it wouldnt convert to .bin, not so sure it wasnt to begin with
 
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