Unitrex 1000 - a.k.a. Far East Generic Design I

Date of introduction:  1977 Display technology:  LED-stick
New price:   Display size:  8
Size:  5.2" x 2.8" x 0.9"
 132 x 70 x 23 mm3
Weight:  2.5 ounces, 70 grams Serial No:  VP 587599
Batteries:  9V  Date of manufacture:  mth 09 year 1977
AC-Adapter:   Origin of manufacture:  Hong Kong
Precision:  8 Integrated circuits:  MOS MPS7560
Memories:  1    
Program steps:   Courtesy of:  Joerg Woerner

Realtronic.jpg (40011 Byte)MBO3000.jpg (34489 Byte)Gracia.jpg (31298 Byte)You are familiar with this Unitrex 1000 calculator? 

You are right, this calculator - and the siblings named Academy, academy memory, Alltronic HK 9805, Bohsei 3000, Bowmar, Cetina ET, Comico 1000, GPM 15, Gracia, Harvard Student H-303, Janon 3000, King Sonic 3000, MBO 3000, Nikjan, Nobility 3000, Noris 3000, Planar Memory, Realtronic, Seneca 1000 and Tronica 3000 - are a nearly perfect copy of the TI-1250. This Unitrex 1000 caught out attention with its unusual [X/Y] key instead the more common [CS] key. 

Dismantling this Unitrex 1000 calculator manufactured in September 1977 in Hong Kong reveals a very cost effective design using a single-sided printed circuit board (PCB) centered around an MPS7560 single-chip calculator circuit manufactured by MOS Technologies connected to an 8-digit LED display, a keyboard assembly and powered by a 9 Volts alkaline batteries.

The unexpected use of the MPS7560 instead the TMS0972 with the featured Unitrex 1000 calculator explains obviously the [X/Y] key, we knew already from the Commodore Model 797M based on the same chip an [EX] key to swap the X- and Y-Registers to simplify some chain calculations. All other features of the MPS7560 seem to be similar to the TMS0972, we noticed with the HR-1001 a 9-digit LED display with just 8 positions populated..

Within the Datamath Calculator Museum we refer this calculator as Far East Generic Design I, probably the cheapest calculator of the 1970s. Don't miss the Design II and Design III.

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Joerg Woerner, February 14, 2023. No reprints without written permission.