Introduction - If you have any usage issues, please Google them yourself
Main content:
(1) inside the <AT89S51单片机试验及实践教程> experimental Proteus simulation!!!! Including the C language and assembly!!!
(2) Add a comment (I was just learning, and there may be some mistakes, hope raised!) Also added a section with information relevant to the experiment!!
(3) I found the problem to be corrected in the original. (There is also a small part of the problem, is still unknown)