Sergei Frolov

My main site and hobby is Soviet Digital Electronics Museum leningrad.su/museum/ Welcome also to my Livejournal blog at sfrolov.livejournal.com

Casio CQ-1 and CQ-2. 1977th. Same functions, CQ-2 has bigger display.

@TomekMalesinski @travisgoodspeed Agree with Casio fx-48, Elektronika MK-51 and Elektronika MK-38, but fx-2500 has not funcitons above 0-9 keys

@sfrolov @travisgoodspeed So Casio fx-2500, Casio fx-48, Elektronika MK-51 and Elektronika MK-38 all run the same code.

MK51, a single-chip RPN calculator from Электроника. The program ROM is on the right side, but bits are not surface visible. Maybe I can reveal them with delayering or a Dash etch.

Merry Christmas and happy New year!

Casio TC-10 Japanese domestic. Calculator, clock with day of week, phone book, currency converter and travel expense account

Some people are questioning the veracity of the claims that a statue of St. Peter in Argentina was struck by lightning on Dec. 17, pulverizing the halo, key, and blessing hand. The Lepanto Institute sent someone to the location to take pictures and confirm the events. The Dec. 17 lightning strike is CONFIRMED and here are additional pictures of the statue. NOTE: the lightning struck the statue, despite there being lightning rods some 30-40 feet above it (second and third picture).

@System11b That's a great solution. I use the same purchased factory boards (to repair oscilloscopes and similar).

The PCB extender board I made for Iskra 12x calculators works fine, now I can actually try to diagnose this one, the card shown is faulty, press any numbers and the entire machine crashes. Link to PCB files and part number will go on my blog. @sfrolov is this of any use to you?

@xxopxe @kenshirriff @Zeptobars I know interesting topic: radiopicture.listbb.ru/viewtopic.php?…

@kenshirriff Perhaps @Zeptobars or @sfrolov could know?

Can anyone help me identify this symbol on a vintage IC? I suspect it is a Soviet manufacturer logo but I looked at bunch of logos (madelectronics.ru/book/prominfo/…) and didn't find it.

@xxopxe @kenshirriff @Zeptobars Factory logos are rarely found inside the crystals. Usually developers draw something personal.

Elka 43 bulgarian calculator (circa 1974) leningrad.su/museum/show_ca…

Many simple calculators have a function to calculate the inverse of a number (1/X). To calculate this function, press "divide" and "equals". youtube.com/watch?v=BB2wmF…

@nanzonet I agree that -CW models have become much less convenient than -MS, -ES and -EX. You have to press a lot of buttons before you realise which menu a familiar function has been moved to. Simply storing a number in memory has become a separate quest.

@travisgoodspeed Some year ago I createrd this table. Blue - own development, yellow - partial, red - full copy, pink - calculators plant purchased (from GI)

@sfrolov Is there a list somewhere matching Elektronika designs to their Western equivalents? I'd like to match up some more die photographs of clones.

Many hours of operation without turning off

Some calculator videos for fans youtube.com/watch?v=lg9QUp…