Stack Super Help is a programmer's utility cartridge featuring:

• 20 Additional BASIC Commands
• Disaassembler and Monitor
• Disk Operating System Support
• 2 Pass Assembler

This is a dump of the cartridge in program form contributed by Blue Cursor.  Load this up, and issue an SYS 64738 to activate.

Here's a link to the manual and a link to the discussion thread over at the Lemon64 forum.