music on Sweat! Starpath proto

[chewy]

what is up w/ the music, for the intro to Sweat! (star spangled banner)- the starpath prototype.  i rocked it on my harmony cart/light 6'r, and on stella- it sound like no other VCS sound programming ive ever heard.....why!

Edited July 23, 2019 by chewy

[chewy]

its so different!!!

[Rom Hunter]

I think it's because it's a Starpath game, making use of extra memory/technical possibilities?
I think Nukey or Thomas can answer this better.

 

 

[Nukey Shay]

It's using a similar method that Pitfall 2 uses: keeping frequency and distortion constant, only adjusting volume (on every scanline, even during the blanking period).  You can see this in Stella's debugger...click the audio tag and you'll see the volume for both channels being adjusted as you step through scanlines.

[iesposta]

Nukey Shay is correct. 

Pitfall II’s DPC chip helps with this technique of just changing the volume register as often as possible to generate in-tune notes.

 

Mappy and Stay Frosty 2 also make music this way with the extended function DPC+ implementation.

 

The home-brews of Boulderdash and Stella’s Stocking make this type of music in their title screens using only programming and without use of the DPC chip. 

 

The music in the tetris homebrew Chetiry is also another example. 

 

But I was impressed when I first heard it in the Sweat Prototype and realized it was done in software around the time Pitfall II was doing it with the DPC helper chip.  

[masschamber]

Shame sweat never saw completion and release easily one of of not the most impressive 2600 game(s)