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FLOATING-POINT BENCHMARK  
 
The following is a program to test the accuracy of floating 
point functions (from Sept. DR DOBBS):  
     10 A=1                
     20 FOR I%=1 TO 2499  
     30   A=TAN(ATN(EXP(LOG(SQR(A*A))))) + 1 
     40 NEXT   
     50 PRINT A  
     60 STOP 
 
The correct printout is A=2500 exactly.                                         
 
IBM-PC BASIC 1.0 fails miserably, giving A=2179.8 (only 1 sig-                  
nificant figure of accuracy!).  In contrast, an APPLE II or                     
Commodore 64 gives 2500 to at least 7 figures. Using the 8087 
with a polyFORTH version of the benchmark, I obtained 2500 to
13 figures in 5.0 seconds. (NOTE: See March,84 D. DOBBS for
the results aginst many systems.)


Press ENTER to continue: 
13 figures in 5.0 seconds. (NOTE: See March,84 D. DOBBS for
the results aginst many systems.)