Canon Palmtronic F-6 scientific calculator from 1975 (kind of rare now?)

[jebem]

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.