Derfler, Frank J. <br/><br/>
TRS-80 data communication systems / 
Frank J. Derfler, Jr. 
 - Englewood Cliffs, N.J. :  Prentice-Hall,  c1982. 
 - xi, 159 p. :  ill. 
<br/><br/> "A Spectrum book." 
<br/><br/><label>Subjects--Topical Terms: </label><br/>TRS-80 Computers).<br/>TRS-80 Model 1 (Computer).<br/>Data transmission systems.