Unusual orange display.ġ200 "Lady" (1975?): The 1200 with more "feminine"-colored faceplate and keys.ġ205 (1976): Another colorful 1200 relation, but this one has oversized lettering too.ġ220 (1976): This (and the 1225) are somewhat obscure, but otherwise ordinary, 1200 series units.
No memory or fixed decimal switch as on 2550. The keys and body style of 2550, painted-on silver trim of SR-10. Another 1200 progeny.ġ50 (1974): Possibly the rarest TI. SR-10 - 1st version (1972): TI's first "SR" (Slide Rule) model.ħ6 - "Spirit of 76" (1976): Red/white/blue Bicentennial (of the USA) model. They are surprisingly difficult to find.ġ680 (1977): This one could re-display previous entries and allowed some primitive editing of those entries.Ģ500 Datamath - 1st version (1972): TI's first pocket calculator.ĥ050M (1976): Handheld printing unit with memory.ĭataMan (1977): Very unusual child's calculator that looks like a robot. Similar styling to the 1200, but a little higher quality.ġ500 (1974): Nifty little unit with thick chrome borders - one of my favorites.ġ600 (1976): The 1600 series consisted of slimmed-down models that prefigured the styling of LCD units. All advertising photos, manuals, and boxes I've seen show the 1st version, though it's far less common.īusiness Analyst (1976): The first in a long line of popular financial calculators.ĥ8 (1977): Replaced with the 58C in 1979.ġ050 (1977): Another entry in the 1000/1025 line, but not nearly as plentiful.ġ265 (1976): Has a blue fluorescent display, unique within the 1200 series.ġ400 (1976): Has a brown carrying case, not the usual black. In the 2nd version, the logo moves down to the upper area of the faceplate. In the first version, the "SR-10" logo is situated in the escutcheon surrounding the display.
Apparently there are also differences in the display angle and brightness (which resulted in Consumer Reports' action).Ģ500 - II (1974): Similar to 2500 but has % key and cheap logo strip that tends to peel off.
(stated on the back of the calculator) the second recharges in 10 hrs. How can you tell the difference? The earlier has a recharging time of 16 hrs. The first earned a "best buy" from Consumer Reports the second earned a retraction from Consumer Reports five months later. Little Professor - 2 versions (1976, 1978): On the early version, the on/off and level switches are on the side on the later version, they're on the front.ĥ8C (1979): Model 58 with continuous memory.ġ270 (1976): Colorful model. The 1200 series styling was used on many other TI calculators and they all shared the annoying characteristic of loose or missing faceplates. (1975): Also often found in the original box. Sometimes found with the PC-100 printer.ġ025 (1977): Often found in the original box. No doubt the best-selling calculator ever.ĥ9 (1977): Surprisingly common, given its expense and sophistication. The year of introduction is noted in parentheses following the model number.ģ0 (1976): You probably know this one. Thousands of calculators in the process), on numerous conversations I have had with other collectors, and on some library research. The judgments are based on my experience searching through flea markets, garage sales, thrift shops, and collector lists (and encountering They also had such extensive product lines at times that their own products must have competed against each other.įor this article, I divided TI calculators into four categories based on degree of rarity. TI had a tendency to replace their calculators quickly with improved or lower-priced versions, particularly during the There are many rare models and a few less-common variations of well-known models. A count through my ownĬollection revealed over 40 different models and there are many I don't have! It would be easy to conclude that all TI calculators are commonly found and not much of a challenge to the avid collector. Anyone who searches for early electronic calculators quickly senses the extent to which TI dominated the market in the 1970s. "Texas Instruments" and "rare" sounds like a contradiction.