05-07-2016, 02:37 PM

Found this one during my last trip to Porto city last week, when looking for vintage books in a old bookstore.

This machine uses a green Vacuum Fluorescent Display with 12 x 7-segment digits.

However, two digits are reserved for minus signals and "memory in use" and "Error" annunciations.

Another two digits are used for exponent.

This leaves 8 digits for mantissa.

After power on, the calculator shows a "0.^00".

2^5 (a^x) produces a good enough result of: 31.999974^00

The usual forensic check gives this result: 12.199423^00

(Degrees mode. 9 sin cos tan tan^1 cos^1 sin^1)

Trying 1000 ln followed by e^x result in: 999.99964^00

And the classic 1 / 3 followed by * 3 gives a result of: 0.9999999^00

A honest result from this 1975 calculator.

Pi internal constant stored value of: 3.1415926^00

Clearing the calculator and doing e^x twice results in: 2.7182804^00

Not as good as a HP-35 machine, but it is not that bad either.

The case is very robust and well built and the keys have a good travel when pressed despite having no mechanical clicking, but at least they never fail to register.

This machine uses a green Vacuum Fluorescent Display with 12 x 7-segment digits.

However, two digits are reserved for minus signals and "memory in use" and "Error" annunciations.

Another two digits are used for exponent.

This leaves 8 digits for mantissa.

After power on, the calculator shows a "0.^00".

2^5 (a^x) produces a good enough result of: 31.999974^00

The usual forensic check gives this result: 12.199423^00

(Degrees mode. 9 sin cos tan tan^1 cos^1 sin^1)

Trying 1000 ln followed by e^x result in: 999.99964^00

And the classic 1 / 3 followed by * 3 gives a result of: 0.9999999^00

A honest result from this 1975 calculator.

Pi internal constant stored value of: 3.1415926^00

Clearing the calculator and doing e^x twice results in: 2.7182804^00

Not as good as a HP-35 machine, but it is not that bad either.

The case is very robust and well built and the keys have a good travel when pressed despite having no mechanical clicking, but at least they never fail to register.