Vintage Electronic Calculators:

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AKA (Label): MODEL NO.SM-818M, Product number (P/N): SM818M (SM-818M),
Keywords/Tags: SM818M (SM-818M)
Date of intro: ~1974, Origin: Japan (List), Dimensions: 156x90x27mm, Weight: 186g,
Power: Rechargeable,
Display: Type = Display (VFD) (List), Digits = 8+1,
Number of keys: 20, #Key-Black: 17, #Key-Blue: 2, #Key-Red: 1,
Keyboard Array (Rows x Columns): 05x04, Keyboard Layout: [MR] [CM] [%] [(Division)] - [7] [8] [9] [x] - [4] [5] [6] [-] - [1] [2] [3] [+] - [0] [.] [C] [=],
Decimal switch: [DECIMAL_AF-2-1/100], Miscellaneous switch: [MEMORY_OFF-ON POWER_OFF-ON], Indicators: ML,
Classification: / Pocket,
Featuring: Procent, Logic-technology: VLSI (Very Large Scale Integration), calculator-on-a-Chip, Memories: 1,
Related with: KOVAC_parts: (Box) SM818M,
Components: 41 ... 7 Capacitor(s), 14 Diode(s), 12 Resistor(s), 6 Transistor(s), 1 IC(s),
Main Components: ROCKWELL: 15330PB; or; ROCKWELL: 15330PC,
Known Serial-numbers: 0506414 | 0517445 | 0523629 (List of all S/Ns from KOVAC)
Collector value: 7.5/10,
Courtesy of: CALCUSEUM (Serge DEVIDTS),
Info: Info from DUDEK Emil:
Bulky calculator made from three pieces of light (gloss) and dark grey (patterned) plastic. A black printed metallic sticker sits in a raised recessed panel at the top with the brand name.
A neutral plastic display filter is tilted and slightly inset but gives a bright, easy to view display.
Just below the display a ridged area contains a small raised panel with a red LED. Yet another black printed metallic sticker surrounds the raised switch area.
The keyboard has raised sections for each key and is surrounded by a patterned light grey plastic. The keys are medium travel with a metallic click.
The logic is let down by archaic RPN and limited memory and the pseudo fixed decimal bug but does have good recovery.
Boards: The main board is fixed to the rear of the case by three metal clips. It is joined to the keyboard assembly, attached to the front of the case, by 15 colored wires.
A third vertically mounted board sits above these with the power supply components.
Remove the two screws at the rear. The front and rear sections then separate easily.
Logic comments:
[C] is used once to clear the last entry and a second time to clear the whole calculator.
The logic is semi Reverse Polish Notation (RPN): to do 4-3 key in [4] [+] [3] [-]
Overflow on the input of a number is suppressed, keying in a ninth digit is ignored. There is automatic constant on multiply and divide only.
Negative numbers are flagged by a minus sign in the far left (ninth) digit thereby allowing full eight-digit negative numbers.
Overflow shows the result and ‘C’ (or ‘E’ if negative) in the far left (ninth) digit and is recoverable using [C]
Divide by zero shows zero and ‘C’ in the far left (ninth) digit and is recoverable using [C]
The memory is an switched accumulation: switch the memory switch to ‘on’ and all results of the equals keys are added to the memory.
Memory store is indicated by an isolated red LED.
You can switch between fully floating (AF), fixed two digit decimal (2) and financial input (1/100) modes. The latter causes [2] [3] [4] to register as ‘2.34’
Overflow in memory stores the result to the most significant eight digits.


Label, name plate / Examples of use
S/N: 0523629

Created: 12-apr-2014, Manual-update: 04-apr-2023, Batch-update: 25-feb-2024             

# Pageloads since 2018: 38             

2 Pic(s),


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