The time display up top is virtually identical to modern-era Nevco hardware up 'till their switch to LED displays 3-5 years ago. 20 red C7 7-watt nightlight/Christmas tree bulbs arranged in a 7-segment configuration per digit, with two orange bulbs forming a colon. This one only goes up to 19:59, newer hardware has a full tens digit, topping out at 30, 60, or 99 minutes depending on the controller. Other manufacturers show much more significant cosmetic changes over the years. (I've been in a lot of gyms, I've seen a lot of hardware revs.) Cosmetic changes on Nevco boards are very subtle--the addition of a round rectangle surrounding their logo; the change from a textual "bonus" light to a split indicator with a "B" in a red box next to a green arrow for alternating possession; the third orange bulb below the clock colon, used as a decimal point when the clock "jumps" to the left in the last minute, to show tenths of a second.
By contrast, Fair-Play made boatloads of changes. Next time I'm home, I should get the staff at Glenbrook North to let me take some pictures of the portable boards we used to use in the back gyms. There's a wide variety of hardware vintage there. Multi-colored dots for period indicators becoming a digit, bonus indicator changes, lighting changes, and the wacky variety of controllers. The newest (early-80s) ones used BCD thumbwheels to set digits, older ones were push-to-increment buttons for each ones and tens digit. The wildest is the player foul displays that use a rotary telephone dial to set them. (The ones I labeled "Dial-A-Foul" in magic marker.)
Neat stuff, but I'm happy to have microprocessor-driven systems now. It's a hell of a lot less prone to failure.
