Question: how to make a reset button on cartridge.

[Wilheim]

Hi, everyone!

 

In order to make a reset button in a cartridge, what lines do I have to short? Does anyone know how to implement it?

 

Best regards!

[ClausB]

I think you have to open the connection between +5V and RD5. That will disable the cart ROM. The OS regularly does a checksum on part of that memory and if it finds a difference, it resets. I think that's only in the XL OS though.

[Mathy]

Hello Wilheim

 

You mean the button that's found on most flash carts? BigBen seems to have found a way around that switch. As in, we don't need it any longer. Unfortunately, I don't know how far he's got and how he's doing it.

 

Sincerely

 

Mathy

 

[Wilheim]

Hello Wilheim

 

You mean the button that's found on most flash carts? BigBen seems to have found a way around that switch. As in, we don't need it any longer. Unfortunately, I don't know how far he's got and how he's doing it.

 

Sincerely

 

Mathy

 

Hi,

 

Yes, I mean like the Flash carts around. I think it does a hard reset by shorting at least two signals. My intention is to reproduce the short as well as the reset of latch flip flop switch to start on bank 0 again.

 

Regards!

[Mathy]

Hello Wilheim

 

As I said, BigBen seems to have found a way to eliminate the need for that button.

 

Sincerely

 

Mathy

[Rybags]

There's no facility for hard reset by cartridge. It could probably be achieved by shorting +5V to GND but that's a real bad idea and the computer would probably not last long.

 

The RD5 method is what you'd call a "soft reset" as it relies on the Stage 2 VBlank detecting the cart state changing which on most machines will jump to the coldstart (on some it will just do a hanging loop until you press Reset yourself).

 

The other consideration is that simply doing that doesn't reset the banking state of the cart. e.g. with Atarimax carts there'll be a default poweron bank where you can safely put the run vector and always have it used but a soft restart leaves the banking in "indeterminate state".

[Wilheim]

There's no facility for hard reset by cartridge. It could probably be achieved by shorting +5V to GND but that's a real bad idea and the computer would probably not last long.

 

The RD5 method is what you'd call a "soft reset" as it relies on the Stage 2 VBlank detecting the cart state changing which on most machines will jump to the coldstart (on some it will just do a hanging loop until you press Reset yourself).

 

The other consideration is that simply doing that doesn't reset the banking state of the cart. e.g. with Atarimax carts there'll be a default poweron bank where you can safely put the run vector and always have it used but a soft restart leaves the banking in "indeterminate state".

 

I want to make a reset button just like the AVGCart and Ultimate SD cart makes in a simpler cartridge model I made. I'm aware about resetting the banking scheme also. That's why I'm planning to add a reset process of the flip flop latch circuit in the same button, by cutting off Vcc to a capacitor that does the trick.

 

Thank you and regards!