Texas Instruments TI-1500 (1st design)

Date of introduction:  April 8, 1974 Display technology:  LED modules + lens
New price:  $69.95, DM 148.00 Display size:  8
Size:  5.0" x 2.6" x 1.0"
 126 x 66 x 26 mm3
Weight:  4.9 ounces, 139 grams Serial No:  1500011364
Batteries:  2*AA NiCd Date of manufacture:  wk 21 year 1974
AC-Adapter:  AC9140, AC9900/C Origin of manufacture:  USA
Precision:  8 Integrated circuits:  TMS0803
Program steps:   Courtesy of:  Joerg Woerner
    Download manual:   (US: 3.2M Bytes)

Introduced in 1974 the TI-1500 was the successor of the TI-2500 Datamath series. In direct comparison the TI-1500 with its rather small, yet stylish chrome-bordered housing it is only about one half of the earlier Datamath's volume and two-third of its weight.

TI-1500_1.jpg (40003 Byte)This original version introduced in 1974 used an odd keyboard layout. The [%] key was placed left from the [0] key instead the usual place in the top row. This minor flaw was corrected with the 2nd design of the TI-1500. 

TI-1500_Disp.jpg (25315 Byte)Due to the high pressure on manufacturing costs some other changes were realized step by step.

The expensive display made of 9 single 7-segment modules
   borrowed from the SR-50 was replaced first with a LED-stick
   manufactured by Bowmar and later with an even cheape
   LED-stick found in the TI-1200.
The two removable, individual AA-sized NiCd-batteries were
   replaced finally with a solder-type battery-pack.

Similar electronics to the TI-1500 was used with the TI-2500-II, the last member of the famous Datamath series. This gives you an idea, why the TI-2500-II uses only two batteries in it's huge battery compartment.

Ken Shirriff studied the United States Patent Application US3934233A describing the TMS0800 architecture and the program code used with the TI-1500 very carefully and was able to create a JavaScript Simulator for the TMS0800 simulating a (slightly modified) TI-2500-II.

Don't miss the Miracle of the Sinclair Scientific!

The TI-1500 design was individual, no other TI calculator used later the idea of that shape and appearance.

The TI-1500 is featured in the Texas Instruments Deutschland GmbH leaflet ER-1975 dated 1975.

horizontal rule

If you have additions to the above article please email:

Joerg Woerner, October 5, 2002. No reprints without written permission.