The Legacy of DOSBox Debugger Bootcom: A Look Back at DEBUG

Microsoft's creation of Assembler (MASM), 'C' compiler, and debugger (CodeView) marked a significant milestone in the world of programming. However, their DEBUG utility remained stagnant, never receiving an official update to handle instructions beyond those of the Intel 8086/8087/8088 processors. Despite changes and bug fixes over the years, DEBUG continued to function largely unchanged.

One notable exception was the addition of Expanded Memory functions under DOS 4.0. This allowed for the tracing of program execution through interrupts using the T command. The P command was also introduced, enabling quick execution of subroutines. Additionally, it became possible to step through COM programs with the S command.

DEBUG's ability to assemble instructions directly into machine code using the `I` command made it a valuable tool for programmers. Although lacking some functionality compared to standalone assemblers, DEBUG remained a popular choice due to its ease of use and flexibility.

The history of DEBUG dates back to 1981 when Tim Paterson created his DEBUG.COM utility while working on Personal Computer DOS 1.00. Later, he was hired by Microsoft to become the primary author of their first operating system. However, Microsoft had already purchased the rights to sell QDOS, which they used as the basis for their own OS.

Tim Paterson's work on DEBUG continued, and in 1982, he released a ROM version that allowed for debugging of QDOS-based systems. The code for this ROM version was later released into the public domain.

In recent years, the legacy of DOSBox Debugger Bootcom has been kept alive through various clones and modifications. These have enabled the use of DEBUG with modern operating systems, including 32-bit code. However, it's essential to note that permission must be obtained from the author before using these clones for any purpose other than personal use.

In conclusion, the DOSBox Debugger Bootcom remains an important part of programming history, thanks in large part to Tim Paterson's original work on DEBUG. Although it may not have received significant updates over the years, its legacy continues to inspire and educate programmers today.

Dosbox debugger bootcom