Superchip Variables Starting?

[KevKelley]

I had noticed that when using the Superchip variables, sometimes I would get funky behaviors if I don't immediately set them to zero at the beginning of my program as if they are already retaining a value.  

 

Is there a particular reason for this or am I missing something?

[+Gemintronic]

I think that on real hardware memory can be dirty and have random values.   So, maybe that's Stella trying to be like a real 2600 at boot.

 

What I'd like to know is if there's a programmatic way to clear SuperChip memory.  Some for .. next loop.  Save some space.

[+Karl G]

6 hours ago, Gemintronic said:

I think that on real hardware memory can be dirty and have random values.   So, maybe that's Stella trying to be like a real 2600 at boot.

 

What I'd like to know is if there's a programmatic way to clear SuperChip memory.  Some for .. next loop.  Save some space.

At the start of any normal bB program, there is a bit of assembly that clears out all of the normal (non-SuperChip) RAM. For on-cart RAM like SuperChip, you may need to clear it yourself. Here's a for loop that can clear all SuperChip RAM at the start of a program:

 

    for temp5 = 0 to 127
        w000[temp5] = 0
    next

 

Edited April 30, 2022 by Karl G

[KevKelley]

4 minutes ago, Karl G said:

At the start of any normal bB program, there is a bit of assembly that clears out all of the normal (non-SuperChip) RAM. For on-cart RAM like SuperChip, you may need to clear it yourself. Here's a for loop that can clear all SuperChip RAM at the start of a program:

 

    for temp5 = 0 to 127
        w000[temp5] = 0
    next

 

Thanks! I had noticed that sometimes I would hit the reset switch and it was throwing me a bit. I was using super chip ram for counters for various things like movement or sound and I thought it strange that things seemed to stick or when I turn it on a sound would play when it shouldn't. I figured there was a good reason.