I couldn't even decisively pin down exactly what year it was first manufactured

Likely 1985.

ajxs 5 days ago | parent | next [-]

I did see this article when I was researching, but it's incorrect. You can find references to the HD44780 in earlier catalogs. The earliest reference I can find is 1981: https://archive.org/details/Hitachi-DotMarixLiquidCrystalDis...

Likely the first year of manufacture was 1981/82.

	▲	userbinator 5 days ago \| parent [-]
		That 1981 document says "preliminary", which suggests very limited trial production. Even the 1985 reference I found is "advance". First tape-out may have been earlier than that. Have you tried asking Hitachi (apparently now Renesas) about it? It's more likely that this information is available on the Japanese part of the internet.

crb3 5 days ago | parent | prev [-]

Try 1972; taped out in 1971.