Thanks to the landlord! I have been troubled by this problem for many years, and there has been no good solution.
The phenomena of this problem are first that Chinese cannot be displayed in 16-bit DOS programs, and second that after running 16-bit programs, not only cannot Chinese be displayed, but also long filenames and scroll bars in the prompt disappear. Although running chcp 936 can return to Chinese, the long filenames and scroll bars disappear forever unless the command prompt window is reopened.
The landlord's method solves the problem of displaying Chinese, but cannot retrieve the long filenames and scroll bars. The most troublesome thing is that some DOS programs cannot be displayed at this time, for example, the content displayed by calling INT21 function 02 is blank.
It seems that this is a bug in the Chinese version. The English versions of 2000 and XP with Chinese fonts installed do not have this problem. I used to replace the Chinese version's ntvdm.exe with the English version's, and the two phenomena of this problem were solved, but 16-bit Windows programs (NE format) cannot be started. Later, it was found that running 16-bit Windows programs caused the English ntvdm.exe to crash.
I wonder if this problem has been fixed in Vista?