Borland Turbo Debugger
Turbo Debugger (TD) is a machine-level debugger for DOS executables, intended mainly for debugging Borland Turbo Pascal—and later Turbo C—programs, sold by Borland. It is a full-screen debugger displaying both Turbo Pascal or Turbo C source and corresponding assembly-language instructions, with powerful capabilities for setting breakpoints, watching the execution of instructions, monitoring machine registers, etc.