Texas Instruments RR-1 Spell-Checker

Date of introduction:  1989 Display technology:  LCD dot matrix
New price:   Display size:  15 char 
Size:  3.2" x 7.0" x 0.7"    
Weight:  5.5 ounces Serial No:  9040018311
Batteries:  4*AAA Date of manufacture:  mth 04 year 1989
AC-Adapter:   Origin of manufacture:  Taiwan (I)
Precision:  10 Integrated circuits:  CPU: Toshiba T84C00A
 ROM: Toshiba TC531000
 RAM: Sanyo LC3518
 Display: LCD-Driver
Memories:  1    
Program steps:   Courtesy of:  Joerg Woerner

Spellchecker_1_Back.jpg (259176 Byte)Texas Instruments introduced already in 1989 this powerful Spell-Checker RR-1. The later RR-2 added a Thesaurus to the Spell-Checker function. 

A much smaller product followed within 1 year, don't miss the PS-3000

What is a Spell-Checker? Type in a word and the Spell-Checker compares it immediately with roughly 97,000 words of its memory. 

We noticed some minor changes of the key printing during production time. Don;t miss the second edition of the RR-1 and focus on the printing of the [ON - OFF] key legend.

Spellchecker_1_PCB.jpg (450189 Byte)Dismantling this early Spell-Checker RR-1 reveals a rather complex printed circuit board (PCB) centered around a Z80 compatible Toshiba T84C00A microprocessor, a Toshiba TC531000 OTP-ROM with 128k Bytes capacity and a small RAM Sanyo LC3518 with 2k Bytes capacity. The single-chip display driver was assembled in reverse direction and hides its type. We assume that the chip was manufactured by Toshiba.

Spellchecker_1_CPU.jpg (39367 Byte)The TMPZ84C00A is an 8-bit microprocessor manufactured in Toshiba's low-power C-MOS Silicon gate technology featuring a power consumption of only 15 mA while operating at 6 MHz. The above sketched architecture was used in a lot of different products with just another balance of RAM and ROM capacity:


Product ROM-size RAM-size Example
Spell-Checker 128k Byte 2k Byte RR-1
Data Bank 64k Byte 64k Byte PS-6700
Graphing calculator 64k Byte 8k Byte TI-81
Modern graphing calc 512k Byte 32k Byte TI-83 Plus


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If you have additions to the above article please email:

Joerg Woerner, Ocober 23, 2009. No reprints without written permission.