I used to write some programs with QB, but QB is really not comparable to the development environments under Windows nowadays. Now I'm developing programs in protected mode for DOS using DWPL. The development environment is Delphi 7, and the running environment can be used with DOS 6x/7x/8X.
And object-oriented programming (VCL classes) can be used, as well as exception handling (TRY...EXCEPT/FINALLY). The program can still continue to run if there is an error, as long as it's not a major problem (hardware issues). Delphi has everything (serial ports, parallel ports, network). What I value most is its network development functions; its examples include TCP/UDP/WEB/FTP. With a little modification, powerful applications can be made. And it can even support multithreading (you can do other things while Sleep(x)). I've been using it for nearly half a year. Are there any like-minded people who can communicate together?