The command line compiler was a separate compiler for when you wanted to use some external method for building (like a batch file) or your program was very big

The command line compiler was a separate compiler for when you wanted to use some external method for building (like a batch file) or your program was very big to compile with the IDE in memory (remember this was real mode with a 640K RAM limit, often less than that was available). But you could take TURBO.EXE (ide+compiler+debugger) and TURBO.TPL (the library), put it on a floppy and work from there. Back when i was a kid, my process to start a new "project" was to take a blank floppy and copy those files (and a couple of units i was sharing) since i didn't have a hard disk. I still have a ton of floppies littered with turbo.exe/tpl pairs. The Turbo C/C++ also needed only a single executable, tc.exe/bc.exe (depends on the version) and the include and lib directories. This is the same with Borland C++ 5.0 i am talking about above, although that one also needs a bunch of DLLs too. Since i don't want to break my installation, i only renamed the bcc32.exe and bcc32i.exe to something else, run the IDE and built my engine. As i expected it worked. Although the fact that you can make modifications and have them compiled without saving the file is also an indicator.