Timbob
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Hello!

So, I was bored and curious, which is always a good combination, and I wondered: Can I connect a LCD to a super gameboy?
As the super gameboy is basically a normal DMG without the screen, I figured it should be possible...

I traced the lines from the lcd, and all the pins used are directly connected to the DMG cpu.
they are all unused on the super gameboy (that basically has the same cpu), except for the 2 data outputs (which makes sense).

After some soldering, this is what I ended up with:

I used the back of a normal gameboy to get the -19 volts to drive the LCD. I could probably work that in later on, but I wanted to test it first.

So tell us Timbob! did it work?
It did indeed! I tested it using kirby. Because kirby is awesome.

After that, I wondered if it would give any strange stuff if I used the super gameboy special features.. painting or changing pallet didn't do anything, but when I started Megaman 5, which is a super gameboy title, I did see some weird stuff


I reset the super nes while playing. The super gameboy reboots, very quick display of the nintendo logo (Sgb doesn't have the scrolling logo), and then you see some glitchy video as the special megaman border is loaded.
after that, the game starts and plays as normal, and I pan to the out of focus tv tongue

So Timbob! does this have any practical use?
None that I can think of really... Just wanted to see if it could be done big_smile
maybe you can build a screen into a super nintendo so you can play gameboy games without a tv... you know. like on a gameboy wink

kitsch
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matt's mind

this is pretty awesome actually.  very neat project

XyNo
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Joliette, QC, Canada

woah nice ! These kind of mods are always awesome !!! Good job Timbob !

herr_prof
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well it would be nice for demos, you can have your display in front of you and the screen output on projector behind you! neat!

Timbob
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Thanks!

Yeah, there are probably some uses for this big_smile
maybe for VJing.
would be fun to see how the little screen reacts if you circuitbend the snes itself. Maybe you could still play the game on the small screen while the big screen shows glitchy stuff.

Or indeed to have a secondary screen which could be usefull for giving demos or workshops.
Next step would be a custom cartridge to include the screen, and of course a backlight. (maybe even a prosound and a linkport.. If I feel up to it wink )

Oh, and kitsch. You've got mail big_smile

Last edited by Timbob (Nov 11, 2012 9:30 pm)

kitsch
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matt's mind

^ yes, i am making a txt file preparing to reply to your email now in fact tongue

thursdaycustoms
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Cleveland, OH

This is awesome. I always wanted to give this a try.
Didn't Nex do something like this once?

thebitman
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Nex drove video out of a Gameboy to a TV, which is basically the reverse of this mod. Very cool nonetheless.

SuperBustySamuraiMonkey
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Madriz, Supain

Is it possible then to put a sgb inside a dmg shell? I mean, isnt the processor supposed to be faster and all?

basspuddle
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washington
SuperBustySamuraiMonkey wrote:

Is it possible then to put a sgb inside a dmg shell? I mean, isnt the processor supposed to be faster and all?

I think only the boot times are faster.

Timbob
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SuperBustySamuraiMonkey wrote:

Is it possible then to put a sgb inside a dmg shell? I mean, isnt the processor supposed to be faster and all?

The processor is basically the same. The only difference is that the scrolling logo is removed. So it boots faster. You can place a SGB CPU in a DMG and it will boot faster, but it won't run faster.

The SGB will run faster then a DMG however, because it has a faster clock. (4.295 MHz instead of 4.194 MHz) but that's hardly useful tongue

nitro2k01
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Sweeeeeeden

I believe the SGB does copy the logo to VRAM just so it leaves the same data in video RAM in case some game looks at this to detect crappy emulators, or something like that.

The glitches are happening because the SGB is using video RAM as a way to transfer data, in this case probably the border shown around the GB screen. The game can send a command to lock the screen output before transferring data this way, which is why you don't see the glitches on the TV screen.

Timbob
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Ooh nitro. Is there anything you don't know? tongue

nitro2k01
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Sweeeeeeden

Yes, I don't know a witty answer to the question whether there's anything I don't know. Oh wait...

thebitman
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Timbob wrote:

The SGB will run faster then a DMG however, because it has a faster clock. (4.295 MHz instead of 4.194 MHz) but that's hardly useful tongue

Keep in mind that the SGB derives it's clock based off the SNES clock, and that you can bypass this signal in the cartridge and wire in a DMG CPU crystal. *cough cough* keep this in mind Kitsch *cough*

Timbob
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thebitman wrote:
Timbob wrote:

The SGB will run faster then a DMG however, because it has a faster clock. (4.295 MHz instead of 4.194 MHz) but that's hardly useful tongue

Keep in mind that the SGB derives it's clock based off the SNES clock, and that you can bypass this signal in the cartridge and wire in a DMG CPU crystal. *cough cough* keep this in mind Kitsch *cough*

The super gameboy 2 has the same speed as a normal gameboy.
The first SGB does run faster. And will play the sound of normal games faster, but I believe LSDJ has a compensation build in to correct the pitch.