Introduces a nonproprietary environment DJGPP for developing 32bit protected mode software in C/C ++ under DOS, and explains that DJGPP accomplishes developing 32bit protected mode software in C/C ++ under DOS by DPMI(DOS Protected Mode Interface).

• 介绍一种 DOS下的 3 2位 C/ C+ + 保护模式软件开发环境 DJGPP,他通过 DPMI ( DOS保护模式接口 )实现DOS下 3 2位保护模式软件的开发。