The Texas Instruments Ti-58c

Display: LED, 8 digits (+2 Sci. Not.)

Power: 2 AA nicads in proprietary package, AC adaptor

Adv. Functions: Trig, logs, stats

Memories: 60

Programming: Keystroke programming, 480 (partially merged) steps, branching, flags

Comments: While the Ti-58/59 calculators didn't have the "built in power" of the HP-67, they were a) cheaper and b) expandable via "solid-state software modules" - essentially ROMs of preprogrammed routines. With their huge memories, this made for a very flexible machine. I think I paid about $120 for this in 1984.