DATAMATH CALCULATOR MUSEUM
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DATAMATH CALCULATOR MUSEUM |
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 |
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| 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 |
| Memories: | |||
| 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.
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.
Due
to the high pressure on manufacturing costs some other changes were realized
step by step.
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• 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.
If you have additions to the above article please email: joerg@datamath.org.
© Joerg Woerner, October 5, 2002. No reprints without written permission.