FTP download stops when mouse clicked down

[Syntho]

On System 7 through OS9 or so I notice that  some programs don't like to run in the background so much. When I use an FTP program for example, the download stops when I click on something. As long as I click and keep the mouse held down, the download is paused, and only resumes after releasing the mouse button. Why is that? It's the same with certain other software too: either the tasks in the program pause, or the gui freezes until the mouse is let go.

I'm guessing that some software (and maybe the OS itself?) was programmed to work on a machine running a single application only and not have stuff running in the background.

 

[Cory5412]

This is the OS itself.

The history of Classic (before 10/X) Mac OS is, as you've guessed, based on running first a single app, then later a low number of apps at once, and not doing an awful lot of background processing. Classic Mac OS was never good at, say, rendering a video in a video editing program or a long animated clip in a 3d program and at the same time checking e-mail or working on an office document.

You shouldn't notice it except in very prolonged click-hold situations, such as if you're scrolling through an extremely long document (for which you may consider keyboard shortcuts such as cmd+arrows) or if something just lands on the mouse button and stays there.