The real MVP here is "Apple 400k Floppy Disk Drive - 6990285A.pdf", without it I'd be there for months.
(ok Mac Almanac II.txt and apple2_IWM_Spec_Rev19_1982.pdf helped too! And probably four other documents!)

Thank god they gave the checksum algorithm (I need it to encode the floppy image to a format digestible by the computer)

#hotkeyEmu #mac128k