A platform game: Mister Butterfly’s five children have each wandered off with a balloon into a cavern, and you must find one child and one balloon on each of five levels. The cavern is full of deadly spiders and bees. Q and A fly up and down, O and P move left and right and the space bar fires; to change platform you stop in the middle of a trapdoor (a grey hole in the floor) and fly up or down through it. The keys can be redefined and a joystick can be used. Rescuing all five ends with “You saved all five of your children… You are a Hero!”.
The title screen reads “Mister Butterfly, ©1987 Byte Power, written by Kristian Boisvert”. It was published on the Byte Power Spring 1987 tape (Issue 7).
Program Analysis
The game is machine code. Its BASIC is a single line that sets black ink, paper and border, loads a 2,846-byte block at 50000 and calls it, then loads the 35,066-byte main block at 27000 and starts it with PRINT USR 27000. The code has not been disassembled here.
Notable Techniques
- Two-stage machine code load from one BASIC line, with explicit address and length on the first
LOAD … CODE. - The 35,066-byte main block loads at 27000 and reaches past 62000, using most of the TS2068’s free RAM.
Image Gallery
Note: Type-in program listings on this website use ZMAKEBAS notation for graphics characters.