ASM-One by TFA (The Freak Association) was THE assembler editor of the Amiga demoscene. Written by Rune Gram-Madsen, it offered an integrated editor, assembler, debugger and disassembler in one program. Features: Fast assembly, Copper list debugging, hardware register monitor, breakpoints, source-level debugging. ASM-One and its successor AsmPro were the most used assembler tools in the demoscene.