MCS-48 and UPI-41 assembly language manual. 
Intel Corporation                                            
 - California  Intel Corporation  1978 
 - [various pagings.] 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Assembly language<br/>Microcomputer system<br/>Universal Peripheral Interface
<br/><br/><label>Universal Decimal Class. No.: </label>12:21.0  / INT