31 : 5/ Electronic Computers 

 Step Operation 



583 



Result 



1 Read in y 



2 Store at memory location y 



3 Store 1.0 at x 



4 Clear and add x 



5 Multiply by x 



Computer learns value of y 

 Computer stores value of y at assigned 



location in its memory 

 Computer stores the first guess, namely 



1.0, at location assigned to x 

 Computer puts x into arithmetic unit 

 Computes x 2 



6 Multiply by — 1 



7 Add?/ 



8 Divide by 2.00 



9 Divide by x 



10 Store result at z 



Computes — x 2 

 Computes y — x 2 

 Computes (y — x 2 )j2 

 Computes (y - x 2 )/(2x) = Ax 

 Stores value of A.v at memory location 

 assigned to z 



1 1 Add x 



12 Store at x 



13 Clear and add \z\ 



14 Subtract 0.0001 



15 



16 



17 



If [(1*1 - 0.0001) > Go to 4 

 [(|*| - 0.0001) < Go to 16 



Read out x 

 Stop 



Computes z + x 



Replaces contents of memory location 

 x with the next guess for x 



Brings absolute value of z into arith- 

 metic unit 



Computes \z\ - 0.0001 



[0.0001 is limit of error assigned 

 here to x] 



Reiterates if Ax exceeds limits of error 



Proceeds if final answer has been 

 reached 



Records final answer 



Computer awaits further manual 

 instructions 



D. FORTRAN program for IBM 650 or IBM 704: 



Note: This procedure would 

 actually be available as a 

 special subroutine labeled 

 SQRTF and does not 

 have to be programmed 

 each time. It is included 

 here for illustrative pur- 

 poses only. 



