Sharp Elsi Mate EL-8118 from the 70's in Japan: yet another VFD based calculator

Sharp Elsi Mate EL-8118 from the 70's in Japan: yet another VFD based calculator - Printable Version

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Sharp Elsi Mate EL-8118 from the 70's in Japan: yet another VFD based calculator - jebem - 02-28-2015 08:46 AM

This unit is in reasonable condition for its age. The case is intact, except a tiny hair line close to the power adapter jack.

The calculator was used extensively, as the worn keyboard membrane shows, but all the keys still register fine as long as we press it firmly.

From the back engraved label:
Rating: (DC) 3V 0.3W
(Dry Battery SUM-3 x 2) 3V
(Rechargeable Battery EA-18B) 2.4V
Or (AC Adapter / Charger EA-17E) 3V
Sharp Corporation
Made in Japan

An additional very worn silver sticker label informs about the patents involved in the manufacturing process.
"Manufactured under one or more of the following patents:
USA ..... UK ..... CANADA ..... "

Hardware details:
- The VFD is bright as new, thanks for the installed excellent FUTABA 9-ST-12 unit.
- The high quality electrolytic capacitors are from Nichicon - They measure fine after more than 40 years!
- 28 DIP IC Hitachi HD37351 SoC, made in 1976 I believe.
- The high voltage transformer was made by TDK Japan.
- The current consumption on this unit is:
52mA after power on (only one digit lit).
65mA with all digits lit.

RE: Sharp Elsi Mate EL-8118 from the 70's in Japan: yet another VFD based calculator - jebem - 02-28-2015 08:56 AM

Some old school function keys here: MU, 5/4
Does anyone have a instruction guide or information on these kind of calculator functions?

RE: Sharp Elsi Mate EL-8118 from the 70's in Japan: yet another VFD based calculator - rprosperi - 02-28-2015 01:33 PM

(02-28-2015 08:56 AM)jebem Wrote: Some old school function keys here: MU, 5/4
Does anyone have a instruction guide or information on these kind of calculator functions?

As I remember the "5/4" setting on Sharp Desktop calculators, but not what it meant, I just had to google a bit.

5/4 means "rounded off" - which is pretty ambiguous, since these same machines also had a "rounded down" and "rounded up" option. I presume this means truncated to the current number of display positions.

RE: Sharp Elsi Mate EL-8118 from the 70's in Japan: yet another VFD based calculator - jebem - 02-28-2015 02:41 PM

(02-28-2015 01:33 PM)rprosperi Wrote: 5/4 means "rounded off" - which is pretty ambiguous, since these same machines also had a "rounded down" and "rounded up" option.

Thank you, Bob.
Following your pointer, I did some testing.

Indeed, in this model, if the 5/4 selector is set to 4 decimal places, I get these answers:
1/3 = 0.3333 (5th decimal digit value below 5, so round down)
1/6 = 0.1667 (5th decimal digit value equal or above 5, so round up)

And this is what I have learn at the engineering technical school in the 70's, but we didn't call it 5/4, so I was not associating it with the rounding rules at all.

RE: Sharp Elsi Mate EL-8118 from the 70's in Japan: yet another VFD based calculator - Don Shepherd - 02-28-2015 11:06 PM

Check with Katie on the instruction manual.

RE: Sharp Elsi Mate EL-8118 from the 70's in Japan: yet another VFD based calculator - Danny - 10-09-2021 04:13 PM

Hi,

I just got a nice EL-8118 myself, and was wondering about some of its less trivial functions.

For exemple, I understand MU is for Markup, but I’m not sure about the order of operands.

I found out that the « a^n » key calculates powers , and that the double arrow key switches between 2 input registers.

That would be cool to find a manual somewhere, even for another ELSI MATE model with similar keys.

Thanks for any help Smile

RE: Sharp Elsi Mate EL-8118 from the 70's in Japan: yet another VFD based calculator - toml_12953 - 10-09-2021 08:09 PM

(02-28-2015 02:41 PM)jebem Wrote:
(02-28-2015 01:33 PM)rprosperi Wrote: 5/4 means "rounded off" - which is pretty ambiguous, since these same machines also had a "rounded down" and "rounded up" option.

Thank you, Bob.
Following your pointer, I did some testing.

Indeed, in this model, if the 5/4 selector is set to 4 decimal places, I get these answers:
1/3 = 0.3333 (5th decimal digit value below 5, so round down)
1/6 = 0.1667 (5th decimal digit value equal or above 5, so round up)

And this is what I have learn at the engineering technical school in the 70's, but we didn't call it 5/4, so I was not associating it with the rounding rules at all.

Statisticians do it differently. They round up if the last place desired is an odd number and down if an even (or some do it in reverse, down if odd, up if even) This way the cumulative errors tend to cancel each other out.

Round to two places example:

4.575 ==> 4.58 since 7 is odd, we round up
4.545 ==> 4.54 since 4 is even we round down