first post . how to find program - Modulus div

[asterysk]

Thankyou for the useful tips.

I have an HP97S (I/O) in working order but no manuals. Have just ordered the USB from MoHPC so should have the documentation in a while to work through.

My aim is to use the HP97 to de-encipher One Time Cipher messages (and also perhaps cypher them).

I am going to use the Mod 10 method (https://www.amrron.com/wp-content/upload...me_pad.pdf) .

This will be my first time programming an HP calculator and the One Time Cipher seems straightforward enough once I work out the Mod 10 division

What I want to do is this : (de-cipher)
1) Store the One Time Cipher on a programmable card (it will be sets of 5 digits 0-9 , 10 sets )
2) Type in the ciphered message (it will be 50 digits 0-9)
3) decipher the message using the programmable card (this is the mod 10 part) , the message will still be a sequence of digits 0-9
4) convert these de-ciphered digits into Alpha Numeric text using a lookup table

The ciphering would just be the reverse

I think this will give me a good intro to the basics before I try something a bit more advanced.

My ultimate aim is to hook the 97S into my autopilot on my boat (as a backup system) and also to use it as a training device for my sextant, both of these are big projects and way down the line when I get some free time !!