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Tech Notes: Wang 400-Series Program Operation Code Table Updated 7/21/2014

This document lists the known operation codes for Wang 400-Series programmable calculators. This includes the Wang Model 450, 452, 462, and 487.



Operation Code   Function                                                                                   
0000 [0]
0001 [1]
0002 [2]
0003 [3]
0004 [4]
0005 [5]
0006 [6]
0007 [7]
0008 [8]
0009 [9]
0010 [.]
0011 [SET EXP]
0012 [CHANGE SIGN]
0013 Unknown
0014 [CLEAR REGS]
0015 [CLEAR DISPLAY]


Codes 01XX through 07XX operate on Memory Registers. The operation performed is determined by the first two digits of the operation code, which is an encoded representation of the seven "Special Function" pushbutton switches with the [Sp] pushbutton in the up position. The XX part of the instruction code is generated when a Function Key (00-15) is pressed to indicate which memory register the selection operation is to be performed upon.

Operation Code   Function                                                                                   
0100 - 0113 Total of Memory Register 00-13
0114 RIGHT [TOTAL]
0115 LEFT [TOTAL]
0200 - 0213 Add Display to Memory Register 00-13
0214 RIGHT [+]
0215 LEFT [+]
0300 - 0313 Subtract Display from Memory Register 00-13
0314 RIGHT [-]
0315 LEFT [-]
0400 - 0413 Multiply number in Display by Memory Register 00-13
0414 RIGHT [×=]
0415 LEFT [×=]
0500 - 0513 Divide Memory Register 00-13 by number in Display
0514 RIGHT [÷=]
0515 LEFT [÷=]
0600 - 0613 Store number in Display into Memory Register 00-13
0614 RIGHT [STORE]
0615 LEFT [STORE]
0700 - 0713 Recall content of Memory Register 00-13 to Display
0714 RIGHT [RECALL]
0715 LEFT [RECALL]


Codes 0800 through 0815 provide various programming functions. The codes are generated by none of the "Special Function" buttons being depressed, and pressing one of the "Function" keys (00 through 15) which is encoded into the last two digits of the operation code.

Operation Code   Function                                                                                   
0800 Search for MARK in Program
0801 Recall
0802 Unknown
0803 Go
0804 Skip if Display = 0
0805 Skip if Display Positive
0806 Unknown
0807 Unknown
0808 Unknown
0809 Unknown
0810 Unknown
0811 Unknown
0812 Unknown
0813 Unknown
0814 Unknown
0815 1/x


Codes 0900 through 0915 provide various programming functions. The codes are generated by the [9XX] "Special Function" button being depressed, the [Sp] mode pushbutton in the down position, then pressing one of the "Function" keys (00 through 15) which is encoded into the last two digits of the operation code.

Operation Code   Function                                                                                   
0900 MARK
0901 Store
0902 Alpha
0903 Stop
0904 Jump if Display Non-Zero
0905 Jump if Error Condition
0906 Unknown
0907 Unknown
0908 Unknown
0909 Unknown
0910 Unknown
0911 Unknown
0912 Unknown
0913 Unknown
0914 End
0915 Return


Codes 10XX through 14XX provide access to various Special Functions as indicated by legends below the Special Function pushbuttons (active when the [Sp] button is depressed). The first two digits of the operation code are encoded by the selected of the Special Function button that is depressed. The particular function accessed is encoded into the last two digits of the operation code by the Function Key (00-15) depressed to enter the program step.


Operation Code   Function                                                                                   
10XX f(XX) (Function Currently Unknown)
11XX F(XX) (Function Currently Unknown)
12XX Execute Function selected by BLACK section on function key label
13XX Execute Function selected by WHITE section on function key label
14XX Exchange content of display and Memory Register XX


Codes 1500 through 1515 also appear to be programming related. Most at this time remain indeterminate as to their function. The codes are generated by the [15XX] "Special Function" button being depressed, the [Sp} mode pushbutton in the down position, then pressing one of the "Function" keys (00 through 15) which is encoded into the last two digits of the operation code.

Operation Code   Function                                                                                   
1500 Unknown
1501 Unknown
1502 Unknown
1503 Unknown
1504 Unknown
1505 Unknown
1506 Unknown
1507 Unknown
1508 Unknown
1509 Unknown
1510 Unknown
1511 Unknown
1512 Unknown
1513 Unknown
1514 Unknown
1515 No Operation

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