SNES Game genie problem
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Re: SNES Game genie problem
Haha great!
Super Mario World is easy to work. So your SNES rev may be 93 below.
PIN 6* from picture is not a /CE real PIN?
Super Mario World is easy to work. So your SNES rev may be 93 below.
PIN 6* from picture is not a /CE real PIN?
Last edited by tbfa on Sat Mar 11, 2017 4:20 pm, edited 1 time in total.
Re: SNES Game genie problem
Sure it is!!
Usually it's connected to /CART.
Maybe it should be pulled low...
Re: SNES Game genie problem
Okay!!!
About DK2, it is one of Champions in cart protection. SRAM checks, and others. It Will be hard to do It works. I have dk3 and never works
About DK2, it is one of Champions in cart protection. SRAM checks, and others. It Will be hard to do It works. I have dk3 and never works
Re: SNES Game genie problem
Well, pin 6 in your picture is actually pin 22 (since the pin 1 key is at the other end). And pin 22 is /CE... so ... yeah, you're disconnecting the signal from the cart edge "/ROMSEL" and since the game is always working it must float low when not driven.
This isn't a good thing; it means that whenever the CPU is reading from RAM, PPU, or APU it'll get in a fight. (But it looks like the Game Genie has some resistors in the way causing the ROM to always lose the fight?)
This isn't a good thing; it means that whenever the CPU is reading from RAM, PPU, or APU it'll get in a fight. (But it looks like the Game Genie has some resistors in the way causing the ROM to always lose the fight?)
Re: SNES Game genie problem
Sorry , with "PIN 6" i mean 6th PIN from mask ROM down side , from left to right direction.
I don't undestand much about snes hardware and logic.
I don't undestand much about snes hardware and logic.
Re: SNES Game genie problem
Isn't this called sort of a race condition?lidnariq wrote: This isn't a good thing; it means that whenever the CPU is reading from RAM, PPU, or APU it'll get in a fight. (But it looks like the Game Genie has some resistors in the way causing the ROM to always lose the fight?)
The bus arbitrer that would solve this problem just can't because of the missing control pin.
This can lead to a program crash, or an exception, if I'm rememebering my architecture classes right.
Re: SNES Game genie problem
Yeah, my best guess is that leaving the ROM enabled all the time speeds things up by enough to compensate for the resistors slowing things down.
It's an answer that I'm not terribly comfortable with, but... I'm not up for tracing the SNES Game Genie PCB at the moment, so I don't have any better data to work with.
It's an answer that I'm not terribly comfortable with, but... I'm not up for tracing the SNES Game Genie PCB at the moment, so I don't have any better data to work with.
Re: SNES Game genie problem
Try connecting /CE to ground and seeing if it still works. If it does, then lidnariq is right about what's going on: grounding /CE and using /OE for all decoding makes relatively slow ROMs respond faster at the cost of more power consumption. I've even seen games that leave /CE and /OE asserted all the time and use a separate 3-state bus transceiver for decoding, such as Holy Diver for Famicom.
Is there a separate /OE on that ROM, and if so, what's it connected to?
Is there a separate /OE on that ROM, and if so, what's it connected to?
Re: SNES Game genie problem
I had put a piece of paper on the /ROMSEL pin.
No success.
But exchanging the resistors to 100 Ohms did made it boot.
Should I care for the 10K pulldowns??
Edit:
Here is the Charles McDonald's notes about the SNES GameGenie Nocash pointed me at the begining. It doesn't have the full schematics, but has most things explained like "this connect in there" stuff.
I'll do some more tests and see what happens!!
No success.
But exchanging the resistors to 100 Ohms did made it boot.
Should I care for the 10K pulldowns??
Edit:
Here is the Charles McDonald's notes about the SNES GameGenie Nocash pointed me at the begining. It doesn't have the full schematics, but has most things explained like "this connect in there" stuff.
I'll do some more tests and see what happens!!
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Re: SNES Game genie problem
In that case use an emulator.Fisher wrote:The pressure here is because of the kids, that really want to play Donkey Kong 2 with the codes.
My current setup:
Super Famicom ("2/1/3" SNS-CPU-GPM-02) → SCART → OSSC → StarTech USB3HDCAP → AmaRecTV 3.10
Super Famicom ("2/1/3" SNS-CPU-GPM-02) → SCART → OSSC → StarTech USB3HDCAP → AmaRecTV 3.10
Re: SNES Game genie problem
So, if I understand Mr. MacDonald's notes correctly ... the GG passes through, or fails to pass through, the /ROMSEL signal to the cart depending on whether there's an address match. If there's a match, it drives a specific value onto the 16-bit data bus (of which only half is exposed on the SNES). If the cart (for whatever reason) ignores /ROMSEL, then the resistors ensure that the GG wins instead of the cart.
I still don't have a better working theory than "timing issues, possibly because a lot of SNES carts swapped /ROMSEL and /RD" as to why cutting pin 22 sometimes helps. Maybe differences in 68k vs 5a22 timing??
For no good reason I'm uncomfortable with the GAL.
I still don't have a better working theory than "timing issues, possibly because a lot of SNES carts swapped /ROMSEL and /RD" as to why cutting pin 22 sometimes helps. Maybe differences in 68k vs 5a22 timing??
For no good reason I'm uncomfortable with the GAL.
Re: SNES Game genie problem
That was the first thing I tried.creaothceann wrote: In that case use an emulator.
But they just don't liked to play on the small computer screen, even with the original SNES joysticks.
Now they're very happy with DK2's invincibility code.
Other than swap these pins functions, maybe Nintendo did some funny stuff with Pin 57 (CPU_CLK).lidnariq wrote:"timing issues
If I understood correctly the GameGenie uses this pin to sync.
Does any game uses it??
Most special chip games I saw used the Pin 1's clock.
I can try to dump it's contents as I've done before with the other PAL ICs, if needed.lidnariq wrote:For no good reason I'm uncomfortable with the GAL.
Fortunatelly, you're the man who interpreted it.
Re: SNES Game genie problem
I don't think so. I think pin 57 is redundant with /RD and /WR; i.e. if pin 57 is high one of /RD or /WR are low.Fisher wrote:Other than swap these pins functions, maybe Nintendo did some funny stuff with Pin 57 (CPU_CLK).
If I understood correctly the GameGenie uses this pin to sync.
Does any game uses it??
In contrast, pin 1 is the ≈21.5MHz master clock.
I, uh. Gosh, I don't think there's really a good reason to bother dumping the PAL until someone's bothered to trace the PCB photos of the rev1 SNES GG.I can try to dump it's contents as I've done before with the other PAL ICs, if needed.
Fortunatelly, you're the man who interpreted it.
Re: SNES Game genie problem
PCs have VGA, DVI, or HDMI out, and HDTVs tend to have HDMI and often VGA in. What inputs does your TV have, and what video outputs does your PC have?Fisher wrote:But they just don't liked to play on the small computer screen, even with the original SNES joysticks.
Re: SNES Game genie problem
Ok.lidnariq wrote:I, uh. Gosh, I don't think there's really a good reason to bother dumping the PAL
since I really can't desolder and resolder that LSI chip, I won't be able to do a nice scan either.
It was very cool to dump the PAL. Unfortunatelly, the last one was used by a GPL violator, wich threw a thread I tought was a suicide note... How fool I was!!
I tried to understand his reasons, but Zepper seemed to have got really angry!!
That's a really nice idea!!tepples wrote: What inputs does your TV have
Unfortunatelly the PC is a little too far from the TV.
I think I'll try to get a 15m cable. That should be enough to be nicelly installed though the attic.
Would this size give some noticable problems?
I'll try to get wireless gamepads too, so the party'll be complete!!
I'm posting a picture of the mod I made, just if someone finds necessary: I just ignored the pulldowns, since I got no trouble up to now.
Again, many thanks for helping me!!
My kids also say thanks!!