Assemble an MS-DOS .COM binary with DEBUG.EXE

The 8-Bit Guy has a video where he demonstrates the assembler built right into the monitor ROM on a C64. This fascinated me and made me wonder… If I was stuck on an old MS-DOS machine and wanted to assemble a binary… Could I do it? Byte by byte? With what tool? Those of us stuck with “IBM compatible” PCs didn’t have no fancy monitor ROMs. Turns out MS-DOS’ DEBUG.EXE is and was entirely up for the job. ...

November 11, 2025 · 1 min