I am aware that there are some issues with the older versions of the DMG-01 CPU and LSDJ but is anyone aware if there are any issues with the SGB CPU and LSDJ?
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SLC, UT
SGB runs slightly faster so the pitch gets messed up a little, it's minimal though.
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Taichung, Taiwan
stargazer wrote:
SGB runs slightly faster so the pitch gets messed up a little, it's minimal though.
The actual CPU?
To my understanding it only ran slightly faster because of the timing crystal on the SGB board.
I presume it should run at "normal" speed if it was swapped into a dmg.
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SLC, UT
Yeah you didn't mention you were swapping it. As to that, I cannot attest to anything.
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The CPU is the same as a normal one, just with the boot scene removed. So it should work normal.
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Taichung, Taiwan
Anyone exerience WAV channel playback issues?
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Are YOU experiencing issues, or just trying to figure out before you buy one?
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Taichung, Taiwan
I have parts ready to swap over. Just wondering if anyone had any of the 411. I'll go ahead and do it and find out.
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The CPU itself works just as good if not better than a DMG CPU when in a DMG. where the pitch issue comes in to play is the sgb CPU in the actual super gameboy. I forget the blah blah of why but basically it runs ever so slightly faster (think it had to do with what the snes actually runs at)
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Matthew Joseph Payne
LSDJ has compensated for the SGB speed difference since a long time ago. Check the changelog...
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SLC, UT
kineticturtle wrote:
LSDJ has compensated for the SGB speed difference since a long time ago. Check the changelog...
Wait, as in I shouldn't hear a difference when I use my SGB? I hasn't been THAT long since I updated...
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The SGB CPU derived its clockspeed from an external source. When in a DMG, it gets its speed from the DMG's CPU crystal. When in the SGB, it is derived from the SNES clock. The difference is like 2.4% speed increase in the Super Gameboy using the SNES clock. It's possible to cut the trace in the board, wire in a DMG crystal, and have accurate speeds. You can also just use a Super Famicom and a SGB 2 which has a link port as well as a dedicated CPU crystal.
The more you know. 
EDIT: But when you go around transplanting the CPUs, you are not transplanting the crystal that creates the timing, you are just moving the chip. They are two separate entities.
EDIT 2: LSDJ is brilliantly coded, as kinectturtle pointed out, to modify the pitch tables to work to compensate for the SGB CPU, not 100% sure if it compensates for tempo too (but I think it does)
Last edited by thebitman (Aug 15, 2013 11:53 pm)
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Shenzhen China
You can try SGB2 if you want to make your clock speed accurate. Also, SGB2 have the EXT data port and you can do all the cool stuff that you can do with your Gameboy original's EXT port!