Tronica 99: Small LED RPN Scientific, 20 keys

[benbradley]

Has anyone seen anything like this? (the one in the middle, obviously)
http://s74.photobucket.com/user/yetanoth...3.jpg.html
I got this circa 1979 as a college student because it "looked interesting." In recent years I've looked online for info. All I've found is that Tronica made many handheld LCD games in the 1980s, and some included calculators, and there's a "Tronica micro" LCD calculator, but I've found nothing about a Tronica LED anything.

It's unique for at least one reason: The keyboard is a 5x4 matrix with 20 keys, and I've never heard of another calculator that does trig/log/exp (is that enough to call it scientific?) with so few keys. It doesn't do scientific notation, but for the size I guess you can't have everything. Runs on a regular 9V transistor battery.

I found the original pic and enhanced the contrast so you can see the legends better (under 7, 8 and 9 are SIN-1 COS-1 and TAN-1) and am including it here:
   

[walter b]

Nice find. What's shifted F and shifted 0?

Aristo designed similar small keyboards though algebraic.

d:-)

[Didier Lachieze]

Interesting, what is the result of arcsin (arccos (arctan (tan (cos (sin 9)))))?

[d b]

What a jewel Ben, and the best first post ever. If possible, I'd like to know the answer to Didier's forensics question too.

Great; another old calculator to "need".

[Didier Lachieze]

After some checks I would say that this Tronica 99 is based on the NS MM5767 chip, same as the Melcor SC600 and the Hanimex 276:



If so the forensics result (from arcsin (arccos (arctan (tan (cos (sin 9))))) ) should be : 8.843762

[benbradley]

(01-25-2016 06:11 AM)walter b Wrote:  Nice find. What's shifted F and shifted 0?

Aristo designed similar small keyboards though algebraic.

d:-)

The posting of that datasheet practically answers the question, and that's a nice find! Now I see where it gets its RPN heritage, I remember some of the National/Novus calculators were RPN.

I remembered knowing what those buttons did years ago, but forgot exactly what until I tried them. The markings on this calc look cryptic, but are clear when you understand. Pushing the shift/function button twice "F TT" puts Pi in the display. Apparently whoever did the typesetting didn't have a Pi symbol or didn't know how to do it, so TT was used as a crude Roman-letter substitute.

The shift-0 legend looks like "1 to the nth." The function with an input of 1 gives 0, 2 gives a (positive) decimal expansion less than 1, and 3 a decimal expansion between 1 and 2. The marking is clearly a bad rendition of ln, or natural log.

I don't have the calculator with me right now, but I'll get it and post the result of that sequence later.

This may not be my first post, from my own records I had an account about 8 or 10 years ago and apparently it got flushed. I haven't had the email address associated with that account for 8 years anyway.

[benbradley]

(01-25-2016 07:29 AM)Didier Lachieze Wrote:  Interesting, what is the result of arcsin (arccos (arctan (tan (cos (sin 9)))))?

Indeed it gives: 8.843762

[Chasfield]

Re: the limited number of keys

There were several early scientifics with few keys. The first Sinclair Scientific gets by with 18. I have a Sumlock Anita 841 with 20 and a Commodore SR7919D with 19.

Commodore and Sumlock Anita specifically went for this form factor to get more use out of tooling used for four function models. I believe that Sinclair got stuck with a warehouse full of four function calculator cases when when Gillette pulled out of a manufacturing deal. These cases were used on various low spec. scientifics, and even went on to be the housing for a low cost multimeter.

Desperate times.

[J-F Garnier]

(01-26-2016 01:05 AM)benbradley Wrote:  

(01-25-2016 07:29 AM)Didier Lachieze Wrote:  Interesting, what is the result of arcsin (arccos (arctan (tan (cos (sin 9)))))?

Indeed it gives: 8.843762

Exactly the same result than on my Novus Mathematician...

Compared to the Mathematician, only the M+x² function is missing.

[Didier Lachieze]

(01-26-2016 03:12 PM)J-F Garnier Wrote:  

(01-26-2016 01:05 AM)benbradley Wrote:  Indeed it gives: 8.843762

Exactly the same result than on my Novus Mathematician...

Compared to the Mathematician, only the M+x² function is missing.

The Mathematician is based on the NS MM5760, similar to the MM5767.

Full datasheet:

• MM5767: "For detailed information on electrical specifications and key operations please refer to the MM5760 data sheet."
• MM5760
  

[Michael de Estrada]

I can't find my Hanimex 276 anywhere. It's like it fell into a wormhole. I think I'm losing my mind.

Well, since I can't find it, I'll post that I get the same 8.843762 forensics result with my Unitrex 90SC.

http://www.msdsite.com/photopost/showpho...ppuser=482