Autonerd
Member
Well, the Pentax KX - 1975 - wasn't the earliest, but it is wonderful.
MX had this feature, as did the K2 DMD (but not the regular K2).
If you're looking for this feature at a bargain price -- Ricoh XR-1 (mechanical) and XR-2/XR-2s (electronic) have it, as do their Sears counterparts, the KS-1000 and KS Auto.
BTW, I'm with you, GRH -- KX is my first and favorite, though I do love my K2, and my Sears KS Auto is my workhorse. I've had little luck finding a working XR-1.
Aaron