Device Driver Construction Particulars

The source code for a sample, albeit unusual, BGI device driver is included
with this Toolkit to assist developers in creating their own. The
demonstration driver is provided in two files, DEBVECT.ASM and DEBUG.C.
This "Debug" driver doesn't actually draw graphics, but instead simply
sends descriptive messages to the console screen (via DOS function call 9)
upon receiving commands. Instead of simply playing back commands, your own
driver would be structured similarly, but would access control ports and
screen memory to perform each function.