Bit Shifter
Offline
Brooklyn NY US

First off -- if there's a thread about this already, apologies in advance. Gave a really superficial and half-assed spin through the forum with my eyes closed and for some reason didn't see anything.

I've successfully loaded LSDJ onto bank 1 of an EMS USB cart. Bank 2's been left empty.

Powering on the Game Boy with the cart inserted, a Nintendo logo scrolls down (as usual) and LSDJ appears (as hoped). Power it off, power it back on, and a Nintendo logo scrolls down and parks center-screen -- so here I'm assuming I'm in bank 2 (i.e. no ROM program to advance to once the Nintendo logo scroll completes).

Problem is, there seems to be no getting back to bank 1. Power off, power on -- every time, it's the presumed "bank 2" behavior described above. It doesn't seem to matter how little or how much time I allow to elapse in the power toggle -- immediate power toggle vs. power off, let sit for 10 minutes, & power back on.

This is my first experience with these carts, and it's worrisome -- if this is standard behavior for these things, it's basically totally unsuitable for any kind of live use.

Is there something I'm not getting here? Any help's really appreciated.

arfink
Offline
Minneapolis

Hrm, this sounds like it might be a case of a defective cart, as I have never gotten stuck in bank 2. Is the bank light on? If it is, then you're stuck in bank 2. If not, then you have some kind of memory corruption.

I suggest you reflash the cart and put something inconsequential into bank 2, and see what happens then.

EDIT: If you're flicking your GB on and off alot on stage, I think that's somewhat problematic in itself IMO. Alternatively, since both banks share the same NVRAM, you could load LSDJ into both of them and forget about it.

Last edited by arfink (Aug 10, 2010 3:44 pm)

nickmaynard
Offline
rochester, ny

this is definitely not standard behavior but i have no idea how to fix it.

mine is giving me a lot of shit lately too. but different problems. i'll post later.

egr
Online
Abandoned on Fire

Possibly related:  I've got one gameboy that refuses to recognize page 1 of the carts.  If I do the power cycle page 2 always works.  I'm guessing it's a connector issue since it doesn't happen on any other unit.

Bit Shifter
Offline
Brooklyn NY US

Thanks for the info, guys. I had no real frame of reference for how these cartridges were meant to behave, so this is helpful.

On further inspection it seems like the cart, if left sitting out for around 15 minutes or more, will then successfully revert to bank 1 on the next power-up. But power-cycle again, and then the Trapped In Bank 2 problem starts all over again.

A second cartridge seems to have the opposite problem -- will boot into bank 1 every time (no light on the back of the cart), and will never boot into bank 2. Pragmatically speaking this is less of a problem for me because, really, fuck a bank 2 -- but the basic fact that the unit's not working the way it's theoretically supposed to is still worrying.

So -- I'm not crazy, right? These two carts are not behaving the way they're supposed to? In other words, there's not some arcane procedural omission on my part (forgot to recite the incantation, etc.)?

nitro2k01
Offline
Sweeeeeeden

Writing LSDj to both bank 1 and 2 of the bank 2'er. Or doesn't the program offer you to do this directly?

arfink
Offline
Minneapolis

Yeah, here is proper operational mode:

Turn on, bank 1. Turn off, then quickly back on, bank 2. Turn off, wait for, say, 10 seconds or so, turn back on, bank 1. Reset by pressing start-select-a-b, and it should only reset the selected game, not return to the menu.

Seriously, put LSDJ or something in both banks. Empty uninitialized banks would totally bork something, I should know.

Last edited by arfink (Aug 10, 2010 5:14 pm)

herr_prof
Offline
Unsubscribe

Somone needs to mod the carts so they forever stay in bank one. I have a spare one if somone with smarts wants to do some detective work. Im guessing there is some capacitor that you can desolder to prevent the power cycle bank switch.

herr_prof
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Unsubscribe

DOUBLE DUTCH

Last edited by herr_prof (Aug 10, 2010 5:22 pm)

arfink
Offline
Minneapolis

My guess is that one could just bypass the bank-switching circuit, which uses a capacitor based circuit to determine time since last power up. with a toggle switch, thus keeping both banks but preventing power-time cycle.

egr
Online
Abandoned on Fire
arfink wrote:

My guess is that one could just bypass the bank-switching circuit, which uses a capacitor based circuit to determine time since last power up. with a toggle switch, thus keeping both banks but preventing power-time cycle.

That sounds like a good option.

arfink
Offline
Minneapolis

You know, the EMS 64mbit carts are inexpensive compared to the competition and made by a Chinese pirate hardware company. It's bound to have some flukes. However, before you try anything drastic, erase the cart with the PC, then put LSDJ into BOTH banks. Just try it. Seriously. Uninitialised banks do cause problems, I have experienced this myself.

EDIT: it occurs to me that a faulty capacitor would cause both kinds of behaviour in 100% of cases. The cap holds a charge that, when seen by the bank switching circuit, send it into bank 2. This cap is not supposed to hold a charge longer than a very short while, allowing for switching back to bank 1 when not flicking the power on and off. But a capacitor which holds too much charge will not allow going back into bank 1, while a cap which won't hold a charge will not allow switching into bank 2. My guess is that they used the cheapest possible electrolytic caps, allowing for manufacturing variance which would explain this kind of behavior.

Last edited by arfink (Aug 10, 2010 5:36 pm)

nitro2k01
Offline
Sweeeeeeden

I'd be up for some detective work, unless arfink really really wants to.

arfink
Offline
Minneapolis

I have an EMS 64mb cart, but it's fully functional. Feel free to rip in nitro, I can't afford to replace mine if I wreck it. hmm

kitsch
Offline
matt's mind

i'm not sure if you've tried this, but put something in the second banks, and see if it helps.  switching to them, when there is nothing to load, may be part of the issue in why things are seemingly becoming stuck after having accessed the empty banks. 

its worth a shot.

nanovoice demo, muddyGB, GB electric drum...  all good apps to try which won't mess with your sav at all...

also, can you check something on the cartridge for me, as it might help...

on the back, bottom-right, of the cartridge (melted into the plastic) is a date code.  something like 1005, 1006A, 0912, whatever...

what is the date code?  the latest PCB revision (which is what the date codes partially reflect, the letter is for more than one batch in the same revision) is 1006A, which are functioning beautifully.  it must be a model EMS is comfortable with as well, because they've been using it the last 200 we got, and usually they cycle to a new one quicker than this...

the date code may reveal a lot. 

as well as putting a ROM in bank 2 of both carts. 

then again, they may just be faulty.  which would be very odd if they are 1006A, not totally weird for some of the 2009 dates, but still odd you'd get two with the same issue (apparently).

you should contact the person from whence they come, and as long as they are in good business terms with EMS, they should be able to work something out (EMS products are guaranteed by EMS, and the buyer (your cartridge seller) can work out an exchange even if your warranty with them personally may be up.  if they are willing, that is.  EMS, after all, wants to keep their wholesale purchasers happy and the person you bought it from can make a personal repair request on your behalf with no issue).

@ nitro: i'll send you a cart to fool around with, my pleasure.  i'll be sending you a little something soon anyways (surprise!).

kitsch
Offline
matt's mind

!!!!!!!

i have an idea!!!!

a big thing i noticed about the 1006A batch of carts is that C3 (the big orangish one, just to be technical) is being left off the board.  I contacted Melody about this, and she said indeed it was intentional.  i was assuming it was a decoupling cap, and my worry as it was mistakenly left out of assembly.

removing C3 shouldn't be hard if you've got a soldering iron handy...

with that being said, i never actually asked what C3 was for, and haven't bothered to follow the traces to ask.  1006A works, C3 is gone, i guess that cap was an issue in the design.

and, since we are on the issue of caps...

possibly smile