> When the original Mac came out, it didn’t have multitasking, either.
What is the author referring to, exactly? I've seen screenshots of the original Mac with multiple windows open on screen.
What is the author referring to, exactly? I've seen screenshots of the original Mac with multiple windows open on screen.
It wasn't until Andy wrote "Switcher" that the Mac supported more than one app, which, the first time it demoed made my jaw drop! Andy is a really smart guy. To be fair, Switcher had limitations due to memory and no hardware multitasking support in the original 68000. It was more like cooperative coexistence than true multitasking.
Multi-tasking really wasn't a thing on PCs much before 1988; I mean, you could do it, if you had a bottomless pit of money with which to buy RAM by the half-megabyte and a 286-class processor and a memory manager like DesqView or a penchant for paying DR big ticket license fees for Concurrent CP/M-86, but otherwise ...?
Time telescopes our memories.
Ahem, the Amiga would like a word...
The 68000 hardware could support preemptive multitasking just fine; what it lacked was a hardware MMU. You couldn't run an OS with protected virtual memory on a 68000 without external hardware support (sometimes another 68000 was used for this!). Accordingly, all tasks on the Amiga had access to each other's memory space and even the kernel's. But the fact that Switcher, MultiFinder, and later versions of Mac OS could only support cooperative multitasking was more a Mac OS limitation than a hardware one.
Yes, exactly. Thanks for clarifying. As you say, the lack of preemptive multitasking was mainly an OS limitation, although a hardware MMU would have really helped. I remember at the time reading about the hoops that Andy had to go through to get Switcher (which, as mentioned in other replies, became MultiFinder) to work. One of the issues was that the single app OS model used a bunch of low memory locations as system globals...on every context switch these had to be saved and restored because each running application could change them. (ouch!)
--Andy Hertzfeld
In the original MacOS, only one program* ran at a time. You could have multiple MacPaint windows, for example, but if you wanted to use MacDraw, you'd have to quit MacPaint.
From a process point of view, this was single-tasking.
Andy Hertzfeld wrote the first multi-process environment for Macintosh, "Switcher." With Switcher, you could have MacPaint and MacDraw (or any combination of as many as four apps) open simultaneously.
https://www.folklore.org/StoryView.py?project=Macintosh&stor...
Only one would control the entire screen, so if you were using MacPaint, the MacDraw (for example) windows were hidden. When you "switched" to another app, it was like side-scrolling the entire screen, the entire desktop scrolled horizontally to the left or the right and another scrolled into view.
Later on, MacintoshOS (pre OS X) acquired its own cooperative multi-tasking capabilities, and when that happened, you could have multiple windows from multiple apps visible on the screen at the same time and switch by clicking on another window.
It was quite the hack for its day, and had a cool UX, it was like having four Macintoshes arranged in a carouself, you could "switch" between processes.
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As another comment points out, there was another thing called a "Desk Accessory" that could co-exist on the screen with a full application. But these were not full applications and had very limited capabilities.
https://www.folklore.org/StoryView.py?project=Macintosh&stor...