Posts: 3,283
Threads: 104
Joined: Jul 2005
RTN is a good idea because it returns you to the user program area in RAM. The equal sign can be cleared with CF A.
You should be able to cleanly stop MED with <-. Exit just suspends program execution (like R/S) and the program is still the active one. You can resume execution with R/S. <- is handled internally to do a clean exit.
Here is the explaining comment from matrixedit.wp34s:
/*
* Interactive editor for matrices.
* Start the editor with a matrix descriptor in X.
* Use the arrow keys to navigate:
* up/down: previous/next column
* f-up/f-down: previous/next row
* Type a digit to enter a number. This will suspend
* the progrom. R/S will enter X at the current row/column.
* XEQ RCL restores the present value to X if you decide
* not to change the cell. Press R/S to continue.
*
* Some hot keys:
* A will start over at (1,1).
* When used outside the editor you will need to specifiy
* a new descriptor first.
* B (labeled 1/x) will call M[^-1] on the matrix.
* C continues at the last position.
* D computes and displays the determinant. R/S or C continue.
*
* We need a few registers for internal use and therefore
* set the stacksize to 4 to free registers A to D.
* Press <- to restore the mode and exit the editor.
* Double precision mode will always be reset!
*
* Register usage:
* A - Matrix descriptor
* B - Current register
* D - Old setup mode
* I, J - Row and column
* K last key pressed
*
* Flags:
* A - Controls big "=" sign
* 00 - Shift state
*
* Fixed labels:
* A, 11 - Start over with new matrix ('A'gain)
* B, 12 - Compute the inverse ('1/x')
* C - Continue with current matrix ('C'ontinue)
* 14, D - Compute the determinant ('D'eterminant)
* 22 - [RCL] recalls current matrix element
* 24 - [f] toggles navigation from horizontal to vertical
* 31 - [ENTER^] (same as recall)
* 35 - [<-] Backspace to exit the editor
* 51 - [^] Navigation up/left
* 61 - [v] Navigation down/right
*/
Other programs will most certainly work differently.
