1. © 2008 D. J. ForemanHW 21 Current PC Operating Systems Uni-programming – DOS Multi-programming – UNIX, Linux – Mac OS/X – OS/2 – Windows XP, Vista, 2003/2008 Server – Note: Windows 3.x is NOT an Operating System

2. © 2008 D. J. ForemanS 50 A table with 2 answer columns 1 2 3 4 5 6 7 8 9 10 11 A B C D E F G H TLC

3. © 2010 D. J. ForemanP 3 LOOPS -1 J=1; A=1; B=4; /* these are “initializations” */ DO WHILE (A<B) J=J*2; A=A+1; /* do some other work here */ LOOP PRINT J operation results J = 1 2 4 8 the output is "8" A= 1 2 3 4 because A is no longer < B

4. © 2010 D. J. ForemanP 4 LOOPS - 2 J=1; A=1; B=4; DO J=J*2; A=A+1; /* do some other work here */ LOOP UNTIL (A=B) PRINT J operation results J= 1 2 4 8output is "8" A= 1 2 3 4because A is now equal to B