Sunday, March 5, 2017

TI-15: Memory and Hidden Memory Arithmetic

TI-15:  Memory and Hidden Memory Arithmetic

Many thanks to Bob Patton, a fellow HP calculator enthusiast, who sent me this information.  One of the door prizes I won from HHC 2016 was a TI-15 calculator which Patton donated.  (I also previously purchased an HP 32 SII).

A link to my previous retro review (October 2016):  http://edspi31415.blogspot.com/2016/10/review-texas-instruments-ti-15.html

Storing Numbers in Memory: A Unique Way

I don’t think I ever seen this storage sequence like the one that is presented in the TI-15.  Almost all calculators have a sequence as such:  ([2nd/Shift]) [ STO ] ([register/variable]).  However to store numbers in memory on the TI-15, the sequence is [ = ] [ >M ] [ = ].

For example, to store 100 in memory, I would press 100 [ = ] [ >M ] [ = ].

To recall numbers from memory, press [MR/MC].  If this key is pressed twice, the memory is cleared.

Hidden Talent: Memory Arithmetic

Patton sent me the information of this neat undocumented feature of memory arithmetic.  The following sequences are:

[ = ] [ M> ] [ + ]:  Add number to memory M
[ = ] [ M> ] [ - ]:  Subtracts number from memory M
[ = ] [ M> ] [ * ]:  Multiplies number to memory M
[ = ] [ M> ] [ ÷ ]:  Division,  M ÷ number
[ = ] [ M> ] [ Int÷ ]: Integer Division,  int(M ÷ number)

Press [MR/MC] to recall the result.

Example

Store 100 to memory:
100 [ = ] [ >M ] [ = ]

Add 10 to M.  (Result: 110)
10 [ = ] [ >M ] [ + ]

Subtract 10 from M.  (Result: 100)
10 [ = ] [ >M ] [ - ]

Multiply 10 to M.  (Result:  1,000)
10 [ = ] [ >M ] [ * ]

Divide M/10.  (Result:  100)
10 [ = ] [ >M ] [ ÷ ]

Integer Division.  Int(M/6) (Result:  16)
6 [ = ] [ >M ] [ Int÷ ]

Special thanks to Bob Hutton!

Eddie

This blog is property of Edward Shore, 2017.

Numworks: Allowing Repeated Calculations in Python

Numworks: Allowing Repeated Calculations in Python Introduction Say we want the user to repeat a calculation or a routine for as lo...