Quick update, I've purchased the earliest known TI-81 (AFAIK), stealing the crown from
CVSoft, who has one from June 1990. The one I've purchased is marked as being manufactured in May 1990.
It might be an engineering sample, but I've yet to open it and checked to see if it has a Toshiba T6A49 CPU as opposed to a T6A49A.
Here is my updated list of ti-81 ROM revisions in order of date from oldest to newest.
I'm still missing a few ROMs before having a complete set (assuming there are no ROM revisions that have not yet been documented) Here is the list of the ones I don't have:
<-- Sent to Kerm's
1.6V <--
Not sure if this one actually exists or if it was a mistake that slipped through someone.
1.8K <-- not anymore!
V2.00
EDIT: I opened it up and it does in fact have a T6A49, meaning it is most likely an engineering sample.
EDIT2: I bought a 1.8K and sent it over to
Pieman7373's house and it has arrived.