Meaning of DEBUG in English
Tool widely used in the old DOS days, though still imlemented in new Windows OS (2000/XP).
With using this it was possible to look at some the DOS data area in memory, assemble and disassemble small COM programs using the 8088 instruction set.
Even today it might be possible to look at the internal workings of at such things as the keyboard buffer, real time clock, interrupt vector table, rom bios chip and the video ram chips and do some low level hard-drive operations like a read or write unique sectors (MBR/Boot sector).
Debug sets up a work area in memory equal to FFFF bytes in Hex, because of it, it's impossible to get into Protected Mode memory area (Memory mode used by new operating system).
Code analysis English vocabulary. Английский словарь анализа кода. 2012