Texas Instruments TI-3510

Date of introduction:  December 1973 Display technology:  Panaplex II
New price:  $99.95 (October,1974) Display size:  10
Size:  8.4" x 6.2" x 2.5"     
Weight:  2 pounds Serial No:  0003272S
Batteries:   Date of manufacture:  year 1974
AC-Adapter:  120 V Origin of manufacture:  USA 
Precision:  10 Integrated circuits:  TMS0106, National Semiconductor MM5314
Program steps:   Courtesy of:  Joerg Woerner
    Download manual:   (US: 1.9M Bytes)

The rare TI-3510 appeared shortly after the formal introduction of the TI-2500, TI-3000 and TI-3500 in September, 1973. At a first glance it combines the wooden keyboard foil known from the Exactra 31 with a metal frame for the ON/OFF switch. Exploring this switch reveals a surprise: The TI-3510 is always powered:

TI-3510_DISP_1.jpg (5750 Byte)T-Position  Reads the time in hours and minutes.

TI-3510_DISP_2.jpg (10648 Byte)C-Position  Normal calculator function known from the TI-3500.

TI-3510_IC.jpg (46166 Byte)Dismantling the TI-3510 gives the answer to the "How was it possible" question. A simple clock chip manufactured by competitor National Semiconductor is wired in parallel to the calculator chip. The former ON/OFF switch simply selects which of the two Integrated Circuits is connected to the power. 

Today it is difficult to understand why Texas Instruments used a clock chip from a 3rd party manufacturer, the later TI-70 and TI-71 alarm clocks used an own design.

TI-3510_Label.jpg (26486 Byte)The above pictures of the Panaplex display demonstrated clearly the main problem of the TI-3510: Within some years of use the segments of the four digits used by the clock faded out. We assume that a lot of TI-3510 were trashed and together with a low production volume - this one is 0003272S manufactured late in 1974 - it is very rare today. 

The TI-3510 was introduced few month after the Corvus 305, a combination of a 10-digit calculator with clock and date function. But these competing twins were not the winner in the calculator-clock combo race, don't underestimate the rare Garrett 2002.

It took another 15 years till Texas Instruments introduced their second commercial desktop calculator with a built-in clock, don't miss the unique TI-5315

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If you have additions to the above article please email:

Joerg Woerner, September 28, 2002. No reprints without written permission. 

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