Zeptotro was released alongside it's bigger brother Femtotro and continues where that intro left off, pushing the entire intro into the screen RAM and some of the cassette buffer. In intro terms that essentially makes it "invisible" since any program linked to it can use everything from $0801 onwards and therefore doesn't even need to be moved into position downwards through the C64's memory before decrunching starts.
4-Mat's music was disassembled and the resulting source code then included directly into Zeptotro's code in order to save space; memory is still tight to the point that the last byte of the scrolling message is positioned right next to the line of the screen in RAM that it's being fed to.
Trivia: despite taking just 1,088 bytes this is still a fully-formed intro with a logo, scrolling message and music which would meet the Intro Creation Competition's requirements. |