Binary Representation of Information 



33 



to perform an odd number of left shifts. This will cause the first 

 bit of our word to be alternately "one" and "zero." 



Other examples of useful commands include commands to per- 

 form several logical operations. In order to describe a few of these 

 commands, reference will be made to Table I. 



TABLE I 



Logical Operations 



O Logical Product 

 10 1 = 1 

 10 = 

 1 = 

 = 



© Logical Sum 

 1 ® 1 = 1 

 1 © = 1 

 © 1 = 1 

 © = 



® Exclusive "Or' 

 1 ® 1 = 

 1 ® = 1 

 ® 1 = 1 

 ® = 



For example, if we have the two words 



A 10101010 



and 



Q, 11001100 

 we can generate the word 



M 10001000 



10101010 

 11001100 



10001000 



by performing the bit-by-bit logical product of the two words A 

 and Q,, that is to say, we can form A O Q = M. 

 If we have the two words 



A 111000111 



000111000 



and 



M 101010101 . . . 010101010 

 we can replace A by M © A giving 



A 010010010 . . . 010010010 

 and as a final example, we can replace A by A © M giving 



A 111010111 . . . 010111010 



These examples merely illustrate the kinds of bit manipulation 

 that are possible, and no attempt has been made to be exhaustive. 

 As one gains experience in using such commands it is possible to 

 discover how versatile this new instrument is as an information 

 processor. Research workers from many diverse fields are con- 

 stantly finding ways to apply such machines to their problems. 



