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 Static 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 Bytes 2k Bytes RR-1
Data Bank 64k Bytes 64k Bytes PS-6700
Graphing calculator 64k Bytes 8k Bytes TI-81
Modern graphing calc 512k Bytes 32k Bytes TI-83 Plus


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