Somewhat disappointing. The tl;dr is that the author uses an off-the-shelf 6502 compression library and just de-interlaces the Hi-Res framebuffer to improve spacial locality.
The reasoning behind the oddball framebuffer layout is handwaved away with "you can probably blame Woz for this" and "possibly to save a few chips on the motherboard".
Well, yes, to both. And the Apple II scan hardware is an absolute masterpiece of the era (surpassed only, IMHO, by the Disk ][ card he invented a year later). That's what we should be talking about.
Comments
Somewhat disappointing. The tl;dr is that the author uses an off-the-shelf 6502 compression library and just de-interlaces the Hi-Res framebuffer to improve spacial locality.
The reasoning behind the oddball framebuffer layout is handwaved away with "you can probably blame Woz for this" and "possibly to save a few chips on the motherboard".
Well, yes, to both. And the Apple II scan hardware is an absolute masterpiece of the era (surpassed only, IMHO, by the Disk ][ card he invented a year later). That's what we should be talking about.