Likewise, Amiga's dialog boxes were completely indifferent to the state of the running application. Under Windows, if the app crashed, covering the crashed app's window with another one just smeared it away into junk. As long as the dirty bit didn't get cleared, Intuition itself would save the contents of whatever got obscured, and put it back when you revealed the underlying window again. In contrast, when you obscured a Window under AmigaDOS2.x (for instance), it just set a 'dirty' bit that didn't get cleared until the application did something to change the screen. If you obscure a window in Windows, Windows leaves it up to the application to re-draw it. It SEEMED like preemptive multitasking compared to Windows, because Windows has always made applications responsible for managing their own window contents. If an application crashed, the mouse pointer still moved, you could still drag screens, and you could still move and uncover windows. To a large extent, Intuition was indifferent to the state of running applications. The Amiga's UI was preemptively-multitasked (and interrupt-driven). I got an "A" for my self-directed art study though, which consisted mostly of learning 6502 assembler :-) Her eyes glazed over when I began explaining assembly language routines. She appreciated what I had accomplished artistically (including various "vector" animations), but understood little of it. I had to demo how I had been spending my time to my real art teacher when she returned. As a result, I taught myself 6502 assembler and wrote fast "vector" graphics routines that I could call from BASIC, as well as routines that let me draw my own text on-screen as well, not constrained to the rectangular grid of normal characters. That got me interested in the fact that the fonts exploited this feature to get smoother curves on-screen, and I began exploring writing my own fonts and doing graphics from inside the assembler/monitor. This allowed you to draw a white line and then draw a pixel-shifted black line on top of it to get thinner lines, which worked great for crosshatching and other fill effects. While playing with things and reading magazines from the stack in the corner of the lab, I learned about how the Apple colors were actually pulled off, and realized that White 1/White 2 and Black 1/Black 2 were a half-pixel offset from each other. That was the level I was at when I started trying to do "art" on the computer. I wrote that same program in Commodore Basic for my best friend's PET (at his house while he spent the time playing Intellivision), TI-Basic, and AppleSoft Basic. It did have an advantage over the "real" Etch-A-Sketch in that you had to hold down a joystick button in order to draw, otherwise the single-pixel cursor would just be moved around. Doing that by re-defining characters on the fly in BASIC was not much fun. I wrote code for all of them - including a program that let you use a joystick or paddle for an on-screen "Etch-A-Sketch" style drawing program that would let you save and restore your drawings. The graphics available from BASIC on the Apple ][+ were crude, but better IMHO than the programmable-character "graphics" available on the early Commodore and TI machines. I decided I did not like the substitute teacher, and luckily for me she had been given the explicit instruction to let me do whatever the heck I wanted to. I was able to get a standing pass out of art class as a sophomore in high school to go work on art projects in the Apple II lab for a couple of months. OTOH, I had little to no interest whatsoever in the internet at first, I couldn't see what was so fasinating about 'diplaying a formatted document on a remote computer'. Coincidently Conway's game of life is why I forked out $80 on a secondhand Apple]['s, C64's, XT's Amiga's, etc, because I'm sure I'm not the only slashdotter who (for nerdy reasons) was fiddling with a home computer in the 80's and shitting gold bricks in the 90's.
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