DATAMATH CALCULATOR MUSEUM |

Texas Instruments TI-1205

Date of introduction: | 1976 | Display technology: | LED-stick |

New price: | Display size: | 8 | |

Size: | 5.5" x 2.8" x 1.4" 138 x 70 x 35 mm ^{3} |
||

Weight: | 6.0 ounces, 170 grams | Serial No: | 1016099 |

Batteries: | 2*AA NiCd | Date of manufacture: | wk 19 year 1977 |

AC-Adapter: | AC9130 | Origin of manufacture: | USA (LTA) |

Precision: | Integrated circuits: | TMS0972 | |

Memories: | |||

Program steps: | Courtesy of: | Joerg Woerner |

Texas
Instruments took in 1976 in conjunction with mathematics educators at two major
universities an initiative to introduce a group of 6 calculators for educational
use. Including the Little Professor,
the limited function ABLE calculator, the colorful
TI-1205 and TI-1255, the TI-30
and the sophisticated SR-51-II,
these calculators helped students understand and use math concepts from
kindergarten through college and career.

The TI-1205 is based on the TI-1200
but includes rechargeable NiCd-batteries instead the standard 9V block battery.
To enhance the readability of the keyboard both the size of the numerals and the
color-scheme was improved.

Disassembling
the TI-1205 with
Date code 1977 LTA and manufactured in May
1977 in Lubbock, Texas reveals an internal construction identical with the
TI-1255. Instead of the 9V battery found in the original
TI-1200/TI-1250
design, the TI-1205 makes use of 2 rechargeable, AA-sized NiCd (Nickel Cadmium)
batteries. The printed circuit board (PCB) of the TI-1205 adds both the charging circuit for
the batteries and a step-up converter to generate the 9V supply of the
TMS0972
single-chip calculating circuit to the design known from the TI-1250.

Please notice that both the Klixon™-style
keyboard and the TMS0972 would support the 4-key memory of
the TI-1255.

Learn
more about the evolution of the TI-1200 between March 1975 and its discontinuation in 1977.

Learn more about the different
Product Labels used with the TI-1200
- here at the Datamath Calculator Museum we classify the featured TI-1205 as
Hardware Version 3A, PCB Type 4 and Product Label Style 6.

The TI-1205 is by far the most colorful and exotic calculator within the TI-12xx
line.

**Fellow collectors -
if you own a Texas Instruments TI-1205 calculator, please report us the
serial number and date code**** from the back of
the calculator for our Database.**

On September 17, 2009 we were able to celebrate reunion of the calculators featured in the TI Learning Center Sales Leaflet CB-272 including three of the rarest portable electronic calculators.

Find here an excerpt from the TI Learning Center leaflet CB-272 dated 1976:

TI-1205.
Four function capability for upper elementary students.
Ideally suited for use with Texas Instruments 4-6 grade level “Elementary Mathematics Concepts with Calculators™” learning kit, the rechargeable TI-1205 meets all the criteria for beginning use of full-function calculators as described in the December 1975 Newsletter of the National Council of Teachers of Mathematics. The TI-1205 features a colorful face with large, easy-to-read numerals. A bright, 8-digit display shows calculator overflow indication, and a negative sign, just to the left of displayed numbers. The TI-1205 adds, subtracts, multiplies, divides – all in full-floating decimal. And there’s an automatic constant for multiplication/division of a series of numbers by one number to or from a series of numbers. Algebraic entry lets students enter numbers and press keys as they would write them on paper. Clearly labeled, easy-to-handle keys provide a positive “click” to assure students that a number has been entered. A separate clear entry key lets them clear a mistake without repeating the entire problem. When
used in conjunction with 4-6 grade level “Elementary Mathematics
Concepts with Calculators”, developed by the © Texas Instruments, 1976 |

If you have additions to the above article please email: joerg@datamath.org.

© Joerg Woerner, December 5, 2001. No reprints without written permission.