A type in program which adds 30 new BASIC commands and allows you to create more of your own.
Some really useful new commands, such as:
"SLOW" to slow the computer down to make very fast arcade games easier to master
"BACKUP" to copy most BASIC & machine code programs from disc or tape
"RENUMBER" renumbers all lines
"REPEAT" gets all keys to autorepeat
Several graphics commands such as INK, PAPER, BORDER, CLS, HIRES etc etc.
Quite a useful DIY utility - a 64 page paperback in excellent condition.