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Texas Instruments Little Professor (1978)

Date of introduction:  1978 Display technology:  LED-stick
New price:   Display size:  8
Size:  5.0" x 3.5" x 1.1"
 127 x 89 x 29 mm3
   
Weight:  3.8 ounces, 107 grams Serial No:  
Batteries:  9V  Date of manufacture:  wk 36 year 1979
AC-Adapter:   Origin of manufacture:  USA (ATA)
Precision:   Integrated circuits:  TMC1993
Memories:      
Program steps:   Courtesy of:  Joerg Woerner

You know this cute math trainer, the Little Professor. Millions and millions were sold in the past 2 decades from this simple but funny educational product. The basic idea behind the Little Professor is opposite to a normal calculator: The child has to type the answer of simple questions like " 3 + 5 = ? ". You can choose between the four basic math functions and four different grade levels. If the child gives a wrong answer "EEE" occurs, otherwise another of more than 16000 different questions is asked.

Prof_78_1200.jpg (41863 Byte)From the technology this Little Professor from 1978 is similar to the TI-1000 calculator of the same epoch. This second version of the Little Professor could easily recognized at the ON/OFF keys and the LEVEL-key to adjust the grade level. Compare it with the first version introduced already in 1976.

LittleProf_ATA0380_1.jpg (169511 Byte)LittleProf_ATA3679_PCB.jpg (201753 Byte)Dismantling multiple Little Professor (1978) devices reveals a surprise - some models use inside a flexible printed circuit board (Flex-PCB) and some a Rigid-PCB. While the first version of the TI-1000 used a TMC1991 packaged in 28-pin SPDIP (Shrink Plastic Dual In-line Package) with Die-up (standard pinout) on a two-sided Rigid-PCB and the second version a TMC1992 packaged in 28-pin SPDIP (Shrink Plastic Dual In-line Package) with Die-down (reverse pinout) on a single-sided Flex-PCB, reversed the Little Professor (1978) the sequence: 

Little Professor (1978-1979): TMC1993 packaged in 28-pin SPDIP (Shrink Plastic Dual In-line Package) with Die-down (reverse pinout) on a single-sided Flex-PCB
Little Professor (1979-1980): TMC1993 packaged in 28-pin SPDIP (Shrink Plastic Dual In-line Package) with Die-up (standard pinout) on a two-sided Rigid-PCB

Consequently the Little Professor (1978) from a later production (January 1980) with Rigid-PCB uses an "unmarked" TMC1993 while a Little Professor (1980) manufactured in September 1980 sports a marked TMC1993.

LittleProf_78_CMP.jpg (48050 Byte)The 5th row of the keyboard (OFF, SET and LEVEL) disturbs the design of the Little Professor. Already in 1980 a new, smaller keyboard was available and this one matched the original design. The picture on the right combines this Little Professor (1978) with the later Little Professor (1980).



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

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