Elwro Desktop calculators (1)

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The purpose of this page is to show only units which I have. Units which I don't have are covered in Elwro Desktop Calculators List.

Elwro manufactured these desktop calculators since 1970s. Early units were clones (some even using genuine parts!) of Busicom Japanese calculators. From simple 4-operation devices these calculators evolved to complex, scientific and in last models even programmable calculators, using not only western, but also Polish components.

WARNING: Technical parameters are parameters of the particular unit. These calculators were made in a hard times, when western components were not easily accessible. It means that some units may have modifications to use replacement components.

Elwro 105LN

Type Simple desktop
Display: VFD, Futaba DG10R
Keyboard: Mechanical switches.
Chip: Mostek MK6010
Display driver: Hybrid JRC IC-3552 or GC-003
Additional parts: Neon bulb power on indicator
Operations: +, -, /, *, decimal places set by rotary switch (0-4)
Second calculator built in Elwro based on Japanese Busicom products, first widely manufactured. Some units used Japanese hybrid VFD drivers, some Polish ones. They were made with Futaba VFD tubes and probably Japanese cases, as they have English markings about high voltage inside. Not buggy, division by zero displays all zeros and can be cleared with C key. Turning on is realised by lever, spring released display cover and turns power on.
Schematic
Unit 1:
Cover opened Cover closed Display
Rear plate. Casing with English text Digits
Polish hybrid circuits another view Polish mains transformer

Unit 2:

Closed with handle slided off Front sticker Still English text, strange "Approved" mark
Rear sticker Keyboard Error after division by 0.
Inside: general view Keyboard: Made in Japan Chip
VFD driver Resistors and capacitors Power supply - Japanese transformer
VFD tubes Tube detail Mainboard solder side.


This is an unknown unit from military office. Probably it's a 105LN, but its front is modified - it has a front glass, not cover, the plastic is fixed using the white polymer, the same as used to mount smaller window in other units. It also has no power lamp. Instead of a typical cover-based power switch, here the slider is used like in later units. The plastic case is made to fit it as the switch is a bit wider than hole in 105LN. Inside, we have Japanese PCB, chip in an old socket and white hybrid circuits without markings, as well as Polish power transistor in supply circuit. Probably a high-crisis unit made when there was a need to make certain number of calculators by all cost, or 1980s rework of a damaged unit (using Elwro's plastic to fix window suggests Elwro's workshop).