seven segment display history

I remember that seven-segment format being used in TTL(Time To Launch)/MET (Mission Elapsed Time) on big signs by NASA in the early to mid-1960's. These were BIG digits that could be read from long distances. The segments were formed by putting together incandescent lights in rows and columns, and a seven-segment rendition made the digits. Also, many sports scoreboards did (and still today) use a similar seven-segment rendition using individual incandescent lamps to form segments. Also, Brent mentioned the HP 9100A using a 7-segment rendition. True, but the much earlier (1963 versus 1968) Friden 130 used a seven segment rendition on its CRT display. It was slightly modified so that the "1" was centered (by slightly shifting the deflection to the left a bit when a 1 was displayed). Also, a number of calculators introduced prior to the HP 9100 utilized CRT displays with seven-segment renditions, including the Victor 3900, and a couple of machines sold under contract under the Busicom brand name, but designed and manufactured by Wyle Laboratories (among them the Busicom 202), as well as Wyle Laboratories' original WS-01 and WS-02 calculators. These machines were all made between 1965 and 1968. The mission-control consoles of the 1960's and early '70's (before CRT displays pretty much displaced discrete displays) typically used projection-type displays, with small incandescent lights for each digit, which would shine through a photomask of the shape of the digit, and be focused on a frosted glass or plastic screen. I had an old digital clock years ago, using transistorized ring counters that used these type of displays. They were very readable, and nice, naturally formed digits, with a nice white digit against at darker background. The clock was made in 1966 if I remember correctly. Wish I still had that thing...it ended up getting tossed out by my parents :-( Rick Bensene The Old Calculator Museum http://oldcalculatormuseum.com