Texas Instruments PS-4000 Pocket Thesaurus / Speller

Date of introduction:  1990 Display technology:  LCD dot matrix
New price:   Display size:  15 char 
Size:  2.9" x 5.0" x 0.60"
 73 x 127 x 15 mm3
Weight:  2.9 ounces, 81 grams Serial No:  60591
Batteries:  2*AAA Date of manufacture:  mth 07 year 1990
AC-Adapter:   Origin of manufacture:  Taiwan (I)
Precision:  10 Integrated circuits:  CPU: Toshiba T9989A
 ROM: Toshiba TC534000
 RAM: UMC UM6116
 Display: LCD-Driver
Memories:  1    
Program steps:   Courtesy of:  Joerg Woerner

This small Pocket Thesaurus is from the hardware and software almost identical to the RR-2 Thesaurus / Spell Checker introduced one year earlier.

Dismantling this PS-4000 manufactured in 1990 in Taiwan reveals no surprises. The printed circuit board (PCB) sports a very clean layout and we identify the major components immediately.

The hardware resembles more or less its predecessor RR2 but is now centered around a Toshiba T9989A Application Specific CPU instead of the original 8-bit Zilog Z80 processor. 

The program/word memory is labelled TC534000, a OTP-ROM with a capacity of 512k Bytes manufactured by Toshiba in Japan.

The data memory of the PS-4000 is rather small with just 2k Bytes capacity. The dismantled PS-4000 makes use of a UMC UM6116 chip.

The display driver of the PS-4000 Pocket Speller makes use of a traditional package but unfortunately is soldered "face down" to the PCB and we can't identify its manufacturer and type.

Don't miss the PS-3000 Pocket Speller with almost identical hardware, using a smaller program/word memory with 128k Bytes capacity. 

The PS-4000 Pocket Thesaurus / Speller is featured in the Texas Instruments Incorporated leaflet Pocket Solutions (CL-1059) dated 1990.

This PS-4000 was donated by Irina Rouzaeva. Thanks!

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If you have additions to the above article please email:

Joerg Woerner, March 17, 2002. No reprints without written permission.