Is there an easy way to find out if the SNES has booted a game?

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meepowl
Posts: 11
Joined: Sat Oct 22, 2022 7:14 am

Is there an easy way to find out if the SNES has booted a game?

Post by meepowl »

Hi,

I've been working on an Arduino-based region/CIC switch and reset mod for the SNES. It reads the controller input for certain button combinations and then carries out the specified function.

I thought this was all terribly clever until I realised that the SNES doesn't read from the controller unless it's booted a game. So if you need to turn the SNES on and change the region/CIC-status before turning off, inserting a game and turning on again you can't.

One option to overcome this is wait for the SNES to start the controller latch or clock and if this doesn't happen for a specified amount of time, send the necessary pulses from the Arduino and read what comes back. There are several downsides to this.

What would be better is for the Arduino to be able to tell whether software has been booted. I have plenty of pins left. Does anyone know if there is anything reasonably easily accessible on the board which goes high/low when software is booted? Something which stays high/low would be ideal.

Thanks.
lidnariq
Posts: 11432
Joined: Sun Apr 13, 2008 11:12 am

Re: Is there an easy way to find out if the SNES has booted a game?

Post by lidnariq »

You could check the SNES mainboard's CIC's RESET output...
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jeffythedragonslayer
Posts: 344
Joined: Thu Dec 09, 2021 12:29 pm

Re: Is there an easy way to find out if the SNES has booted a game?

Post by jeffythedragonslayer »

lidnariq wrote: Mon Mar 13, 2023 5:33 pm You could check the SNES mainboard's CIC's RESET output...
This only means that the CIC is convinced that it's a genuine cart, right? I would look at the PPU output.
lidnariq
Posts: 11432
Joined: Sun Apr 13, 2008 11:12 am

Re: Is there an easy way to find out if the SNES has booted a game?

Post by lidnariq »

On the SNES, there's no other relevant question. The PPU output will be active (although black) if it's not in reset.
meepowl
Posts: 11
Joined: Sat Oct 22, 2022 7:14 am

Re: Is there an easy way to find out if the SNES has booted a game?

Post by meepowl »

Thanks both. I'll try the reset pin on the CIC.
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