□ □
[□] □
[] □
and then I used a little kerosene lamp behind it ... Douglis used a fairly simple scheme in which the two caches competed for RAM on the basis of how recently their pages were accessed , rather like a normal global replacement policy arbitrating between the needs of multiple processes , keeping the most recently-touched pages in RAM . We used a new math curriculum that tried to connect classroom work to real world applications . Silverman had used a similar approach in V. fischeri to discover LuxI and LuxR-the enzyme that produces autoinducer-1 and the receptor that recognizes it . In 1984 , Apple unveiled the Lisa , which used a graphical user interface ( GUI ) , developed originally at Xerox Corp. ' s Palo Alto Research Center ( PARC ) .