Texas Instruments TI-58C Pool Water Analysis

Date of introduction:  1979 Display technology:  LED-stick
New price:   Display size:  10 (8 + 2)
Size:  6.4" x 3.2" x 1.5"
 162 x 81 x 37 mm3
Weight:  8.5 ounces, 240 grams Serial No:  7183855
Batteries:  BP1A Date of manufacture:  wk 17 year 1979
AC-Adapter:  AC9131 Origin of manufacture:  USA (ATA)
Precision:  13 Integrated circuits:  TMC0501E, TMC0591, CD2400, CD2401 TMC0573
Memories:  0-60    
Program steps:  480-0 Courtesy of:  Mark Bollman

TI-58C-PWA_Back.jpg (377640 Byte)The main disadvantage of the TI-58, the non-permanent program storage was corrected with the TI-58C. Using a low-power C-MOS memory (an unknown chip in this machine) battery drop caused by the NiCd's itself was quicker than drop caused by the memory.

TI-58C-PWA_ModulePCB.jpg (58050 Byte)TI-58C-PWA_Module.jpg (74421 Byte)The TI-58C continued the usage of the Solid State Software Modules™ with up to 5000 program steps introduced with the TI-58 and TI-59 already in 1977. On the backside of the TI-58/59 you'll notice a small lid with a place for a module. The Master Library with 25 different programs was included, a lot of other modules were available.

We know five different approaches of the module expansion:

bulletStandard modules like the Master Library use only the small sticker above
the A,B,C,D, and E keys.
bulletOther modules like this Pool Water Analysis developed by Olin Corporation
make use of a colorful keyboard mask.
bulletCustomized calculators like the USMC AV-8C calculator or insurance calculators
sold by Allianz and others use special keyboard arrangements.
bulletThe CAL-Q-TAX calculator uses an extender instead the usual drop-in modules.
bulletThe Kodak Q-700 Program Adapter makes use of a snap-on cover with an
individualized printing.

TI-58C-PWA_PCB.jpg (476639 Byte)Dismantling the Pool Water Analysis calculator reveals a standard TI-58C calculator manufactured in Spring 1979. It is one of the very early models, the printed circuit board (PCB) of the calculator was manufactured in Canada and makes use of some blue wires.

The calculator was available till the year 1983.

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© Joerg Woerner, October 1, 2002. No reprints without written permission.