THE TWISTOR 



1335 



Fig. 13 

 driven. 



A 320-bit experimental twistor memory array. The arraj- is transi.stor 



mainder of the flux reversal process is by an incoherent rotational process. 

 During this latter time the circular and axial voltage waveforms are 

 virtually identical. 



Fig. 12 gives the range of operation of 2-mil 83 Ni, 17 Fe wire as a 

 twistor operated by mode A. As a result of the extreme squareness of 

 the ^-NI characteristic in helical direction the range of operation en- 

 closes an area nearly the theoretical maximum. The switching times of 

 other memory cells tested ranged from 0.2 /xsec for a 1 mil 4-79 moly- 

 permalloy wire to 20 )usec for a 5 mil perminvar wire. Thus it is seen 

 that the switching speeds of the twistor compare quite favorably ^\ith 

 those of conventional ferrite toroids and sheets. 



It is, of course, possible to store many ])its of information along a single 

 magnetic wire. The allowable number of bits per inch is related to the 

 coercive force, the saturation flux density, and the diameter of the wire. 

 For the nickel wire, about 10 bits per inch are possible. Predictions as 

 to the storage density for a given material can be made bj' referring to 



