Code Machine features and Editor/Assembler, and a separate Monitor/Disassembler. Both programs are entirely self-contained, and are written entirely in Machine Code. From the box: "used in conjunction with a good Machine Code book, it will help you understand how machine code works. For the 48K ZX Spectrum, might also be used with the 128K machines, the TC-2048 computer, as well as with the TS-2068 or TC-2068 with a Spectrum ROM Cartridge. With original box in perfect shape and original manual.