@kelli217

1 year ago

I've been an occasional reader of Greg Naçu's blog pages talking about his design decisions and other challenges. This is an amazing achievement, right up there with Adam Dunkel's Contiki. There just isn't enough space on the VIC-II text screen to show very much. And with UI gadgets and other elements like borders and title bars all around, it's compromised even more. GEOS, for all its glacial (pre-global warming) speed, managed to use bitmap graphics to circumvent that limitation. Even just an 80×25 screen would make a world of difference. The simulated 80 columns of Contiki's second release also come to mind. I know—I know... that using a bitmap screen is a big memory hog. A text screen takes 1000 bytes (not even 1K!) and a bitmap screen takes 8 times as much, and twice that if you're using double-buffering. That isn't even getting into things like color maps and sprite pointers. Greg's managed to get 5 screens in there, switchable, and he's still only 62.5% of the memory footprint of just one bitmap. So, obviously, he's made some deliberate choices. He's favoring speed and compactness over information density. Plus a bitmap screen has the problem of attribute clash, so a text screen is actually more practical for color. Not that a text screen doesn't have its own color limitations, but at least the color isn't going to be split up in ways that break across the middle of a UI element.

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