Reset button (userport) questions on Vic-20

[eightbit]

I have one of these userport reset switches coming (see pic) with the hopes that it will work with the Vic to begin with. And second, it will perform a complete reset. I think I may be out of luck on the second one but before I connect this to the Vic I wanted to get some opinions.

 

The userport reset is advertised for the C64, but from what I am to understand it should work with the Vic as well as they share the same lines this uses for reset (pin 1 and pin 3). But I wanted to make sure. Has anyone used one of these with their Vic-20?

 

And if so (if it works) how is the reset function? If you have a cart game loaded in a ram expansion for example, does it just reset back to the game? Or does it perform a fresh reset as if you toggled power?

 

I recently purchased an SD2IEC device that is also a 32K cart (in one device) and it has a reset button. It loads everything you throw at it. But, if I load a protected cart image (retail carts) they load fine but if I press the reset button on the SD2IEC cart it simply resets to the title of the game. I have to manually turn off the Vic and back on to get back to basic in order to load FB again. Trying to avoid that power cycle each time if possible

 

So, do you guys think this will work at all? Or is it simply going to add another reset button that acts like the one on the SD2IEC on the other side of the machine?

 

 

[brain]

The Final Expansion cart you have is indeed resetting everything.

 

The problem is that the BLK5 RAM (which I believe cannot be accessed by BASIC, so never gets cleared is still mapped into the address space, and still have the original contents in it.  Those original contents include a special signature set of bytes "CBM80" I recall, that the KERNAL looks for on boot.  If it exists, the KERNAL skips BASIC init and jumps right to the game.

 

So, to fix, you have to get the RAM unmapped from $a000 (BLK5).  THat's tougher to do on some units.  UltiMEM maps ROM back into that space on reset, but it appears FE3 does not.

 

Jim

 

[eightbit]

Thank you for your response. It is what I had figured. So at the end of the day this rest switch is just going to perform the same function as the reset on the cart itself.

 

I am actually not using a FE cart, but something else that performs equivalently But I see why they do not force full reset/unmap of BLK5. Some games require a "reset" after load in order for them to work. If the "hard" reset (clearing that area of mapped memory) occurred....well...the game would never be playable. 

 

I wish this cart had two reset switches. One that were "soft" (to reset those games and make them play), and one that were "hard" (like what the UltiMEM does) to really reboot the machine.

 

I guess we can't have it all

Edited December 2, 2019 by eightbit

[carlsson]

As a side note, it is fully possible to direct the BASIC interpreter to BLK5. It is quite uncommon to do that, but I've seen one or two cartridges containing a pre-tokenized BASIC listing at $A000 and then the pointers to variables go to regular RAM. If you map RAM to BLK5 you can have both, e.g. if you need to use the onboard memory for graphics.

 

Also a soft reset only clears the first few bytes of RAM where you program would start. Rest of it will be left intact.

Edited December 2, 2019 by carlsson

[eightbit]

I received this reset userport adapter from Germany today and it does indeed work in the VIC-20, but it also does the same exact thing as the reset button on my RAM/SD2IEC cart....as I expected. Oh well, now I can reset from both sides of the back of the machine I suppose. Can't have enough reset action...lol!

Edited December 3, 2019 by eightbit