Why MacPaint’s Original Canvas was 416 Pixels Wide
Bill Scott (via John Gruber):
The key to this really fast render operation was the use of the Motorola 68k’s MOVEM command. MOVEM stands for Move Multiple. It can take a range of registers and move bits from an address into the M68k registers or do the reverse.
Wow. That’s interesting. I always wondered why it, among all other programs, didn’t use normal windows.