Adler 80 C

Adler 80 C 

The german business machines manufacturer TriumphAdler from Nürnberg, Germany
distributed in the 1970ies several pocket calculators, probably licensed products, under
the names "Adler" and "Triumph".
From that era, the mid 1970ies, the Adler 80 C presented here originates. It is a very
elegant, flat but rugged pocket calculator with only basic calculation capabilities.
As the inventory number indicates, those calculators were used for ambitious and
representative purposes as in banks. And by the way, the shop "Finkenzeller", who
sold this calculator was a quite wellknown shop in Munich.

back side 

Case
The case construction and design are pretty unusual: The squareedged case, which is
slightly convex on the upper and lower side is surrounded on the sides and on the back
by an aluminium cover. If this cover is slided in top direction, you can access the
battery compartment, which holds either four AAA cells or an 4.8V NiCD accu. This
rechargable cell can be charged via a 2.5mm jack on the lower side of the case.

back side with removed cover 

As usual on these old calculators, the rechargable block is a weak point here, too: It is
sealed pretty well, but when it is completely discharged, for example after a long storage time,
it loses almost all of its capacity and leaks. Although because of the good sealing, only a very
small amount of electrolyte can get into the battery compartment, it is still enough to corrode
the contacts.
The accu block is made by Varta, one of the most famous german battery makers that time and offers
the (from todays' point of view ridiculously low) capacity of only 90mAh. For comparison, modern
NiMH AAA cells today already extend the 1000mAh barrier.
Inside the accu block, there are four 1.2V cells, connected in a row. You can easily imagine the
mess inside, when all of them leak.
Construction
The construction of the 80 C is pretty modern, the CPU and external componenty use
way less room, that on calculators, which are just one or two years older. Due to the
small size of that pocket calculator and the resulting squeeze inside, it is very
difficult to see the CPU without desoldering the keyboard.

CPU view  as good as possible 

Display
The flat VFD tube with its row of contacts on the broadside were cutting edge technology that
time and also perfecly readable, bright and roomsaving the same time. Compared with a LED display
of 1975, you can see the worlds laying inbetween.

display view, sideways 

The keyboard is of a rather simple quality: The keys don't offer a click point and if
you press them, you never know for sure, if they work or not. The "x"key already stopped
working most of the time. This bad keyboard is a pity, since the rest of the calculator
is of a much higher quality and deserves a better keyboard.

inside view 

Calculation capabilities
The calculation capabilities of the C 80 are rather simple, but sufficient for financial
usage: Apart from the usual four basic calculating functions, it has got a percentage
automatics and a constants function for all four calculating functions.
This calculator adds and subtracts with a socalled "commercial" calculating system, which
reminds a bit of the reverse polnish notation (RPN): To add two numbers, you have to press
the "+" key after the second number, too, for example 2 + 3 + , which results in "5".
Subtraction works the same way, except, that the first number has to be followed by a "+" keystroke.
For calculating 52, you have to enter 5 + 2  to get the result of "3".
If you had entered 5  2 = instead, the "2" would have stayed in the display; if you
had entered 5  2  , you would have calculated (5)2 instead, resulting in "7".
From todays' point of view, this entry logic seems quite confising, but it originates from the
mechanical calculating machines, which were use the past decades and made the switch from them
to a pocket calculator quite easy.
A word about the overflow logics: When a result extends the display range of 8 digits, it
is shown with an "C" (or "E" on negative numbers) in front. The rest of the number has to be
multiplied by 10^8.
If you for example get an result of E1.2345678, it means, that the true result is
in the range of 1234567890 to 1234567899. The last (ninth) digit is lost and cannot be
restored. If you press the "CI" key, the overflow lock is removed and you can go on
calculating, but you have to keep in mind, that the number in the display has to be
multiplied by 10^8.
Summary
The Adler C 80 was a contemporary office calculator in 1975, whose
entry logic and calculation power resembles of mechanical calculating
machines. For switchers, this was ideal, but for beginners, there were
better and more suitable pocket calculators on the market.
Technical data
Manufacturer  Adler 
Model  80 C 
Year  1975 
CPU  NEC µPD943 
Display  8+1 digit VFD 
Number of keys  19 
Functions  +  * / % 
Entry logic (classification)  ALG ((BCCC)) 
 1 + 0.000 =  1. 
0 / 0 =  Error 
 Power supply  4xAAA 
Size  12,0 x 7,4 x 2,1 cm 
Serial Number  67.503.267 
Condition  AB 

Factsheet 