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Texas Instruments TM 990/301 Microterminal

Date of introduction:  1978 Display technology:  LED-stick
New price:   Display size:  8 
Size:  5.8" x 3.1" x 1.4"
 148 x 78 x 36 mm3
   
Weight:  5.3 ounces, 150 grams Serial No:  9947040001
Batteries:    Date of manufacture:  year 1984
AC-Adapter:   Origin of manufacture:  
Precision:   Integrated circuits:  TMS1000NLP
Memories:      
Program steps:   Courtesy of:  Joerg Woerner

The TM 990/301 Microterminal was introduced in 1978 as a small console for the TMS9900 based computer system TM 990/100M.

TM990_301_CMP.jpg (101015 Byte)This Microterminal is obviously based on a normal TI-30, the most successful scientific calculator of that time frame. 

TM990_301_PCB.jpg (123855 Byte)Dismantling the TM 990/301 Microterminal discovers a completely different internal construction. Instead the small printed circuit board (PCB) of the TI-30 and all the other calculators using its housing we notice a big PCB based on a TMS1000 single-chip microcomputer. Remember that the TMS1000 is still recognized as the first true microcomputer and found its way into millions of products.


A similar approach using a standard calculator housing for industrial products could be found with the TI-510 PLC Programmer.


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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.