"So this is a program that has to run with reasonable performance on a 12MHz 80286 with 2MB of RAM. Are you sure you wouldn't consider having your UI read and w

"So this is a program that has to run with reasonable performance on a 12MHz 80286 with 2MB of RAM. Are you sure you wouldn't consider having your UI read and write the disk directly?" I wrote code for those machines, and no, I wouldn't write my UI code to read and write the disk directly. "Separation of concerns is a modern luxury." This is a myth. Merely an excuse for poor API design. Proper abstraction doesn't mean inefficiency. Your last paragraph (the "Edit") is almost offensive. The cause of bloat is not separation of concerns. It's that people just don't care about writing efficient code (or they just don't know how). Did you ever write code in the era you speak of? Because your statement comes across as ill-informed conjecture.