Commodore - SR-4148R


Brand: Commodore
Model: SR-4148R
Type: Scientific calculator
Picture: Commodore SR-4148R
Batteries: Internal accu
Lifetime: Introduced: ca. 1975
Terminated: unknown
Notes: This is a scientific calculator with two memories, statistic functions, angle conversions and parenthesis. Some of the functions listed below are also found in other Commodore calculators, such as the Commodore SR-1800. A main difference between the SR-1800 and this one is the number of keys. Except for the reverse trigonometric functions there's only one function per key (no "INV"-key required).

Some nice and some less nice features that are worth mentioning:

  • The "d-r"-key not only switches between "degrees" and "radians" mode, but also converts the number currently in display from one angle mode to the other. For example, when the calculator is in "degrees" mode, and the number 180 is displayed, pressing the "r"-key will convert the angle to π degrees. When the calculator is in "radians" mode, the rightmost dot on the display is lit.

  • The "→P" and "→R" keys convert between vector modes. The parameters need to be present as "x" and "y", and can be entered using the "x↔y"-key. The results can be read using the same key.

  • The "EE↑"-key and "EE↓"-key shift left and right in scientific notation. However, when the number shifts out of display, the number is truncated. This can not be used to round the number, because no rounding off takes place.

  • The "Σ1"-key is what is nowadays usually denoted by "M+", it adds the number displayed to the first of the two memories.

  • This calculator feels quite fast.

  • This calculator as a built-in rechargeable battery. Most of the time when I find a calculator with a built-in battery the battery leaks and is often beyond repair because of that. This one however is different, the battery is working fine at the time of writing (September 2006) and still keeps its charge. Even so I took them out as a precaution anyway.
    The internal rechargeable battery exists of three AA rechargeables made by BEREC.

Many thanks to Arnoud Helmantel for finding this calculator for me.


A power adapter.

©2023 Ernst Mulder