GP32 Blu+ Fix Help (normal Sdk)


jbb

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May 28, 2003
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Hi guys,

I'd like to fix my latest program (Bolcataxian) to work on BLU+.
I have a BLU and it works fine on it... but it's been reported as malfunctioning (flicker on right side of screen) on BLU+, after its wider release through the ADIC04 contest.

I do NOT use Mr Mirko SDK, just the normal GamePark SDK... so I am a bit puzzled that it doesn't work.
Any easy fix? I've seen here and there that you just need to recompile with some new options?

Any help would be greatly appreciated.
Cheerio,
JBB
 
Contact Aquafish, he has quikly recompiled his multifirmware to work on BLU+.
He knows the way.
 
Unfortunately aquafish cannot really help, his solution was for a different issue it seems.

Anybody else? (who has succesfully fixed his code NOT relying on MrMirko or Fenix libs)
Has Gamepark issued a statement of some form by the way? ...with a HOWTO doc on how to fix programs to match their bloody new screen specs? Surely?!

If not, I might have to do a few versions "blind", and try out various tweaks through remote beta tester(s). Any BLU+ owner up for it?

Cheerio,
JBB
 
Thanks for trying to fix it. This game is really great.

The glitch seems to be simular to the one in giana's sisters v90 demo, and I thought someone mentioned it was a refresh rate issue?

If you need quick testing of new betas, just post them here and I can get back to you probably that day, christmas break and all.

Have you tried other refresh rates, or slightly higher system speeds?

Good luck and thanks for the free game,
mth411
 
If not, I might have to do a few versions "blind", and try out various tweaks through remote beta tester(s). Any BLU+ owner up for it?
I'd like to help with making Bolcataxian work on BLU+, so if in need of a betatester, you can find me in
IRC (Nick: Dr_Jekyll, in IRCnet, quakenet, efNet) via ICQ (87149555) or drop me a line at dr.jekyll AT gmx DOT li :)

Tho you'd get more helping hands if you'd simply post the betas here at the forums
 
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It looks indeed like a very similar bug I had right after I decided to run the GP32 at 133Mhz for Bolcataxian. The usual SDK functions (GpSurfaceFlip) didn't seem to wait for the VBL anymore (was working fine @66Mhz), and I had to go manual (with a while{} loop).

Weird, it all got fixed in the end as I now wait with my loop (at least) long enough before flipping screen, and I have a triple screenbuffer, so we shouldn't see any massive flicker!

JBB
 
It looks indeed like a very similar bug I had right after I decided to run the GP32 at 133Mhz for Bolcataxian. The usual SDK functions (GpSurfaceFlip) didn't seem to wait for the VBL anymore (was working fine @66Mhz), and I had to go manual (with a while{} loop).

Weird, it all got fixed in the end as I now wait with my loop (at least) long enough before flipping screen, and I have a triple screenbuffer, so we shouldn't see any massive flicker!

JBB
GpSurfaceFlip doesn't wait for VBL at all, so if your code was working at 66mhz without a loop then it was a fluke more than anything else. As the problem has appeared again on the BLU+ it looks like it runs at a different refresh rate. This means that those of us relying on a loop to stop flickering will need to get things tested on both the old and new screens and find a loop delay that will work on both :(.
 
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It looks indeed like a very similar bug I had right after I decided to run the GP32 at 133Mhz for Bolcataxian. The usual SDK functions (GpSurfaceFlip) didn't seem to wait for the VBL anymore (was working fine @66Mhz), and I had to go manual (with a while{} loop).

Weird, it all got fixed in the end as I now wait with my loop (at least) long enough before flipping screen, and I have a triple screenbuffer, so we shouldn't see any massive flicker!

JBB
GpSurfaceFlip doesn't wait for VBL at all, so if your code was working at 66mhz without a loop then it was a fluke more than anything else. As the problem has appeared again on the BLU+ it looks like it runs at a different refresh rate. This means that those of us relying on a loop to stop flickering will need to get things tested on both the old and new screens and find a loop delay that will work on both :(.

ok then the mission is to find an good gpclock setting :)
i have no blu+ then i can't test.
 
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Is there no such thing as:

while (!VBLANK){ }

There is no register/memory location that can be checked for this?
Well technically there's no such thing as vblank on an lcd screen ;).

Mr.Spiv created some vblank emulation code (http://www.cs.helsinki.fi/u/jikorhon/condev/gp32/dl/vblank.c) which looks like it reads the porch settings from the registers so it *should* work on all gp32's, but I've never tried it myself. If you're using Mirko's sdk then it's possible this code is already in there (I think a lot of Spiv's code ended up in Mirko's sdk in some form or another).
 
Last edited by a moderator:
Is there no such thing as:

while (!VBLANK){ }

There is no register/memory location that can be checked for this?
Well technically there's no such thing as vblank on an lcd screen ;).

Mr.Spiv created some vblank emulation code (http://www.cs.helsinki.fi/u/jikorhon/condev/gp32/dl/vblank.c) which looks like it reads the porch settings from the registers so it *should* work on all gp32's, but I've never tried it myself. If you're using Mirko's sdk then it's possible this code is already in there (I think a lot of Spiv's code ended up in Mirko's sdk in some form or another).

jbb said:
I do NOT use Mr Mirko SDK, just the normal GamePark SDK
 
Last edited by a moderator:
Is there no such thing as:

while (!VBLANK){ }

There is no register/memory location that can be checked for this?
Well technically there's no such thing as vblank on an lcd screen ;).

Mr.Spiv created some vblank emulation code (http://www.cs.helsinki.fi/u/jikorhon/condev/gp32/dl/vblank.c) which looks like it reads the porch settings from the registers so it *should* work on all gp32's, but I've never tried it myself. If you're using Mirko's sdk then it's possible this code is already in there (I think a lot of Spiv's code ended up in Mirko's sdk in some form or another).

jbb said:
I do NOT use Mr Mirko SDK, just the normal GamePark SDK
If you were paying attention you'd see that I'm replying to pea not jbb.
 
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