Multitasking in Workbench 1.3?

[itix]

I was decompressing a DMS file to DF0: the other day whilst at the same time trying to create a new drawer on my HD. When creating the Drawer the floppy disk writing would stop until I'd completely finished creating the drawer and let go off the right mouse button.

This happens because on Amiga when accessing menus it blocks all gfx output. It was one of many tricks to make system more efficient. It still multitasks but anything trying to display new gfx content on that screen is blocked.

There is a utility called MagicMenu which replaces standard blocking menus by non-blocking menus but it is also much slower.

[itix]

OS4.x also has optional non-blocking menus, probably using the same kind of mechanism. Does MorphOS also have them? Can't recall if I've ever tested.

In MorphOS it is always non-blocking. IIRC MorphOS inherits its menu system from AROS where it is the same.

[itix]

The reality is somewhat different. Amiga always had (and still has) "tasks" and "processes". While a Unix process can´t easyly access another processes memory and have a lot of overhead, there was a need for some sort of more lightweight multitasking. Hence the invention of threads. So Amigas tasks resemble threads in many ways.

Amiga tasks and processes are practically the same thing. Tasks have some limitations (no DOS access) but they are scheduled just like they were processes and vice versa.

One could say in Amiga all tasks and processes are just threads running under kernel.