Programmable calculator Casio fx-2700P (from ~1981)

[BartDB]

Hi,

Recently a colleague brought to me a Casio fx-2700P Programmable calculator. It is from approx. 1981.

After installing new batteries and checking that everything worked, I thought I'd try writing a little program for it.

Some interesting features:
Besides the M memory, it has 6 "K" memories addressed with Kin and Kout. They support register arithmetic +, -, ÷ and *.
It has 2 conditionals x>0 and x<=M both of which if true loop to the first line of the program.
The programming is blind, so programming steps are not visible as you type them in. Just type the sequence and hope for the best (i.e. test with a few known results).

I decided to try a program that calculates the area of a circle or the volume of a sphere given the value of the radius.

Enter the radius as positive for area or negative for volume.

Code:

Code:

Kin 1        Save in K memory 1
Kin*2        Multiply and save in K memory 2
Kout 2       Recall K memory 2
+/-          Change sign
Min          Save in M
Kout 1       Recall K memory 1
x<=M         If true goto first line else goto next
Kin*2        Multiply and save in K memory 2
Kout 2       Recall K memory 2
x^2          Square result
sqrt         Square root of result (these 2 steps make it positive)
*            Multiply
pi           with pi
=
Kin 3        Save in K memory 3
1
Kin 2        Re-initialise K memory 2
Kout 3       Recall K memory 3

Initialise:
1 Kin 2

The last 4 steps are only really necessary to re-initialise K memory 2, to make repeat calculations easier.

As the loop is back to the first line of the program, it becomes difficult to have an initialisation part at the beginning of the program, hence the need to manually initialise with "1 Kin 2" before running the program for the first time. Re-initialisation is done at the end the program so that consecutive runs of the program do not need manual initialisation.
.

[grsbanks]

Same family as the fx-180P and fx-200P that started it all in the Casio fold. Then the fx-3600P and its ilk. I have a few in that family.