what was it programmed with?
What was it programmed with?
Inb4 gentoo
probably just assembler for whatever microcontroller drives it, probably something very simple like a PIC or indigenous Casio equivalent
...
Allah's will.
It's likely all done in hardware. A microcontroller is overkill for a watch even today and they were bigger,more expensive, and a lot more power hungry in the 80s.
Start with a crystal oscillator at some frequency that can be easily divided down to seconds. Divide down with binary counters (D-flip flops in sequence). More counters for minutes, hours, days. A bunch of AND,and OR gates to get the appropriate 7-segment digits to light up.
in the early 70s maybe, but by 1991? not really, you definitely still might not be wrong, but a microcontroller makes more sense especially since the F-91W logic is pretty much entirely contained in a single chip
Machine language
microcode