Unless otherwise directed by program codes, the execution of a program continues through the steps in numerical order.
C = (F - 32) * 5 / 9
The program will assume that the user entered the degrees F before pressing GO. The following program will perform the conversion. Not, the "01 05" is a direct register number, and the code is entered by setting the "10" toggle switch ON (all others OFF) and pressing the 05 key. Since no other special codes are being entered in this program, the toggle switches need only be setup once and whenever the "01 05" code needs to be entered simply press the 05 key.
STORE DIRECT 01 05 3 2 - DIRECT 01 05 5 × DIRECT 01 05 9 ÷ DIRECT 01 05 RECALL DIRECT 01 05 END PROG
Note, the above keys (except for END PROG) are the same ones that would be used to perform the conversion manually, using the Wang 700 as a simple calculator.
Place the calculator in Learn mode (or Learn and Print) and enter the above codes. If you used Learn and Print, or List Program after entering it, you should have the following listing on the printer:
0000 04 04 000l 0l 05 0002 07 03 0003 07 02 0004 04 0l 0005 0l 05 0006 07 05 0007 04 02 0008 0l 05 0009 07 09 00l0 04 03 00ll 0l 05 00l2 04 05 00l3 0l 05
Note, the END PROG code is not printed by the List Program function.
Now go back to Run mode, press PRIME, enter a number of degrees Fahrenheit, and press GO. You should see in the display the number converted to degrees Celsius.
This program is included with the distribution. You should be able to load it using the tape drive. It is named "celsius.w7t".
This example uses the DIRECT register access functions, however it is possible to use the X and Y display registers together in math operations, and that can simplify a program.
Subroutine calls are made by using codes 00 00 through 03 15, and require use of the toggle switches and keys 00 to 15. Executing one of these codes will cause a "call" (Search-and-Return) to the step MARK'ed with the same code. For example, 00 00 will make a subroutine call to MARK 00 00. A subroutine ends with a RETURN code, which causes the program to resume at the step after the call. Note, a complex subroutine may have multiple exit points, each with its own RETURN.
In addition, there are "Skip" codes that test some condition and then skip the next two program steps if that condition is true. Note, 2 programs steps is the number required for a SEARCH command. If less than 2 steps are required, the remaining may be filled with GO commands. The basic skip commands compare the X and Y display, or test the Program Error state.
|Skip the next 2 steps if the Program Error condition is true. This also clears the error condition.|
|Skip the next 2 steps if Y is greater than or equal to X|
|Skip the next 2 steps if Y is equal to X|
|Skip the next 2 steps if Y is less than X|
There are additional jump codes:
|Skip the next 2 steps if Y positive (Y ≥ 0)|
|Skip the next 2 steps if Y zero (Y = 0)|
SKIP IF ERROR
|Skip the next 2 steps if Y negative (Y < 0)|
|Skip the next 2 steps if Y not zero (Y ≠ 0)|
|Skip the next 2 steps if X positive (X ≥ 0)|
|Skip the next 2 steps if X zero (X = 0)|
|Skip the next 2 steps if X negative (X < 0)|
|Skip the next 2 steps if X not zero (X ≠ 0)|