Texas Instruments SR-16

Date of introduction:  October 25, 1974 Display technology:  LED modules + lens
New price:  $99.95, DM 298.00 Display size:  8 + 2
Size:  6.3" x 3.1" x 1.5"
 158 x 78 x 38 mm3
Weight:  9.2 ounces, 262 grams Serial No:  114394
Batteries:  3*AA NiCd Date of manufacture:  wk 35 year 1975
AC-Adapter:  AC9200, AC9130A Origin of manufacture:  USA
Precision:  8 Integrated circuits:  TMS1001
Logic:  Chain    
Memories:  1    
Program steps:   Courtesy of:  Joerg Woerner
    Download manual:   (US: 4.4M Bytes)

The electronic slide rule SR-16 was the last calculator using the extreme wedge shaped housing of the SR-10 and SR-11. It was superseded by the SR-16 II in a more conventional housing within one year. 

With the SR-40 prototype an upgraded version of the SR-16 II was developed but never introduced to the market.

The colorful design of the SR-11 was dropped for a style similar to the later SR-50A. Technically the calculator was very similar to its predecessors, one interesting feature could be found in the higher accuracy of some calculations. If you are interested in the calculating accuracy of scientific calculators, don't miss the Calculator forensics.

SR-10_PCB3.jpg (138045 Byte)SR-16_PCBA.jpg (169318 Byte)SR-16_PCBB.jpg (58015 Byte)The internal construction of the SR-16 is similar to the late SR-10 Version 3, compare them for yourself.

The featured SR-16 with Date code 355 from the final production run was manufactured in August 1975 by Texas Instruments in their Lubbock, TX facility. Dismantling this SR-16 reveals a design centered centered around a TMS1001 single-chip calculator circuit and supported by two digit drivers for the 12-digit LED display and powered by three AA-sized rechargeable NiCd batteries or disposable alkaline batteries. Please notice the rather unusual display compared to earlier versions of the SR-10, SR-11, and SR-16 calculators.

Today the SR-16 could be called both an historically important and rare calculator. Interested in really rare calculators? Don't miss the TI-150

sr-16_PCB.jpg (166191 Byte)The TMS1001 used with this calculator was the first LSI MOS chip of the TMS1000 Microcomputer family.

The picture at the right gives you a comparison between the first TMS1000 based calculator chip and one of the last ones found in a TI-30 STAT manufactured 13 years later. In the meantime we located a BA-35 Business Analyst manufactured in 1996 using a CD4571B based on the TMS1000 family, too and giving the architecture a lifespan of 22 years.

horizontal rule

If you have additions to the above article please email:

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