| 1 | / |
| 2 | / |
| 3 | / D S Q R T |
| 4 | / |
| 5 | / VERSION 5A 4-27-77 PT |
| 6 | / |
| 7 | SECT DSQRT |
| 8 | JA #DSQRT |
| 9 | DPCHK |
| 10 | TEXT +DSQRT + |
| 11 | / |
| 12 | DSQXR, SETX XRDSQ |
| 13 | SETB BPDSQ |
| 14 | JA .+3 |
| 15 | BPDSQ, F 0.0 |
| 16 | XRDSQ, F 0.0 |
| 17 | DARSAV, F 0.0 |
| 18 | F 0.0 |
| 19 | DSQ2, F 2.0 |
| 20 | F 0.0 |
| 21 | SNGL, F 0.0 |
| 22 | F 0.0 |
| 23 | ORG 10*3+BPDSQ |
| 24 | FNOP |
| 25 | JA DSQXR |
| 26 | / |
| 27 | 0 |
| 28 | DSQRTN, JA . |
| 29 | DSQ1, F 0.0 |
| 30 | F 0.0 |
| 31 | /PICK UP ARGUMENTS |
| 32 | BASE 0 |
| 33 | #DSQRT, STARTD |
| 34 | FLDA 10*3 |
| 35 | FSTA DSQRTN |
| 36 | FLDA 0 |
| 37 | SETX XRDSQ |
| 38 | SETB BPDSQ |
| 39 | BASE BPDSQ |
| 40 | LDX 1,1 |
| 41 | FSTA BPDSQ |
| 42 | FLDA% BPDSQ,1 /ADDR OF X |
| 43 | FSTA BPDSQ |
| 44 | / |
| 45 | /DO GENERAL TESTS ON THE ARGUMENT |
| 46 | / |
| 47 | STARTE |
| 48 | FLDA% BPDSQ |
| 49 | JEQ DSQRTN /RETURN IF 0 |
| 50 | JLT DSQER /<0 ERROR |
| 51 | FSTA DARSAV /SAVE DOUBLE |
| 52 | STARTF /F MODE + ROUND |
| 53 | FSTA SNGL /SAVE |
| 54 | / |
| 55 | /GET INITIAL APPROXIMATION BY CALLING |
| 56 | /SINGLE PRECISION ROUTINE |
| 57 | / |
| 58 | EXTERN SQRT |
| 59 | JSR SQRT |
| 60 | JA .+4 |
| 61 | JA SNGL |
| 62 | FSTA SNGL /FIRST APPROX |
| 63 | STARTE /BACK TO E |
| 64 | / |
| 65 | /TAKE N ITERATIONS OF |
| 66 | /X(K+1)=1/2(X(K)+X/X(K)) |
| 67 | / |
| 68 | LDX -3,0 /3 TIMES |
| 69 | DSIT, FLDA DARSAV /GET X |
| 70 | FDIV SNGL /X(K) |
| 71 | FADD SNGL /X(K) |
| 72 | FDIV DSQ2 /DIVIDE BY 2 |
| 73 | FSTA SNGL /X(K+1) |
| 74 | JXN DSIT,0+ /ITERATE |
| 75 | FLDA SNGL /GET ANSWER |
| 76 | JA DSQRTN /RETURN |
| 77 | EXTERN #ARGER |
| 78 | DSQER, TRAP4 #ARGER |
| 79 | \f |