Gameboy Player PCB

Really stange results. But I guess you saved me from trying to replace the crystal with something different Do you know what that soldered on resistor does?

 

Instresting topic, I might take another look at gameboyplayer card. (Pal, never got a gc and/or disk)
I was intrested into seeing if I could read the LCD bus and start it like a normal gba, taking an gba appart (non-destructive) for reverence.
Do we know if the bios is any diferent or just the same as normal gba?

The resistor is connected to TP3 on the cpu? if i see some other websites it looks like a fix (reset fix?) http://www.gc-forever.com/forums/viewtopic.php?f=26&t=1703
so might just be there but in smd pakageform and on the pcb.
http://problemkaputt.de/gbatek.htm#gbagameboyplayer and more have intresting info to research

I have no direct clue on what the second ic near the connector to gc does (its sort of command and controll/translate? )
Its connected to atleast the lcd, buttons and other pins.

source for many info http://problemkaputt.de/gbatek.htm#pinoutscpupinouts but you probeby already saw that while googleing or bing.

 

It might not be enough to simply apply power. I had to have the startup disc running before the GBA part would turn on. If I remember correctly, when you turn the GC on the bus is powered and you've got 80MHz on one of the pins even without the startup disc, so you might need to drag one of the pins hi/low to activate the GBA. I could be wrong though. Good luck!

He's talking about the TH resistor bridging TP25 and C18 in the picture on the first post of this thread.

And I have no idea why it's there, Bearking... It wasn't on mine or any other pictures I've seen. Weird.

 

I can't remember if the bios is the same or not but I do remember that if it is different then it is not by much. I can actually dump the Bios off of my GBP. Would anyone like me to?

 

I'd be interested.

I know GBA & GBA SP have the same BIOS, at least for USA, but I don't know about GBA Micro or GBP. I checked TOSEC and they don't have any hashes for GBA BIOS.

 

According to this they're all the same, but it never hurts to check. If someone can hook me up with a copy of the BIOS dumper (first two links I got were dead, and yeah I'm kinda lazy...), I'd join in - I just happened to dig out one of my GBMs yesterday, and setting up the GBP wouldn't be too much of a hassle either.

edit: nevermind, the "NOR card" link works so I can use that, just the libfat one is down.

 

Interesting. The DS uses a different BIOS in GBA compatibility mode. Apparently Nintendo changed the BIOS but didn't fix the MIDI lookup bug that is exploited to dump it.

 

I actually coded a dumper before.
https://www.dropbox.com/s/81r7ti6123y02le/GBAUtilityTools.zip

I just gotta dig and my gamecube and stuff and I'll dump the bios. I'm lazy so someone may beat me to it.

 

My board has the resistor as well. Seems like the revision later has a smd version near the testpads extra. Next week ill try somethings (power, scope, lcd?, disconnect the dol ic)

 

Done. My AGB-001, OXY-001 and DOL-017 all had exactly the same BIOS w/ a md5 of a860e8c0b6d573d191e4ec7db1b1e4f6.

 

ok then there should only be a difference in the bios when it comes to the DS stuff.

 

I'm just chiming in to say I'm really interested in any developments on getting the vertical refresh for the Player closer to the Gamecube's. A stutter every couple minutes would be perfectly fine, but the stuttering every few seconds becomes pretty distracting quickly enough. Very odd that different-valued crystals on the clock source gave the same result. Wish I knew more about circuitry to help out.

 

bumping this to ask if there is any progress .... or is it abandoned at this point?

 

Neither of both on my side. I try to do some tests "soon" because i dont own a gc or player disk, it will be "can i run it (headless) without a gc. But i can only promise that ill upload some pictures and try powering it someday soon. (its hot here and currently doing xbox stuff, and school project takes lots of time)

 

I'll freely admit I may be doing it wrong, using the wrong kind of parts, etc. I don't even know for sure what Y1 is.

It's good to see that other people are interested in this too. I actually got a quote for custom frequency crystals before I tested the stand-in crystals. If someone can figure this thing out I'd be willing to buy a batch.

Might I suggest checking the local classified ads for a cheap GC? I've gotten them for as little as $5 from yard sales. A "broken" one (bad drive only) would work fine, assuming you're using a softmod to replace the missing startup disc - assuming that's possible, I'm not real familiar with that stuff, although I hear it works.

 

I don't think you can go completely driveless. You could replace the drive with sth like a Wiikey Fusion, but that'd be another ~$25. Anyways, cubes with intact drives aren't all that expensive either, I've seen them go for as low as €5 + shipping. Then there's a few bucks more for a XenoGC to replace the missing GBP boot disc with a copy.

 

You're right. I looked it up on gc-forever wiki and you need at least a quasi-working drive to do anything. It ain't like the ps2 where I sometimes forget the drive on my fat model can't read discs at all!

 

you can always install a wiikey fussion or wasp chips that are drive replacements, you then load the GBP iso from the sd and it works

 

For crystals you can also can find some that can be controlled by an external voltage, not sure how precisely they work but ive seen a classmate work with a few to change speed at run time to match that of a Target board. for this Gc thing you can maybe try different speeds to see what works on your tv. Better yet, try a frequency generator and match a clock with that?
I already have a Wii(with some gc games), and this gc player is hopefully a workig GBA. Else I might sell this off because I don't like to have hundreds of different consoles and no games at all.

 

A VCXO wouldn't be helpful, a PLL would--but you'd have to somehow get the GC's Vsync signal, divide it by 2 to get a 50% duty cycle, then multiply it up by the GBA's line frequency and pixel prescaler. Just changing the Xtal, even if you could get a precise 59.94/60.05 Hz wouldn't work because the two would be out of phase and in a constant state of drift.

Plus even with the frames in sync you'd still have to modify the software to buffer and display them synchronously. If you're going to go through the trouble of modifying the software you could probably get away without modifying the hardware at all by employing a better asynchronous rendering technique that avoids the offending artifacts.