Guru
Joined: 07/08/2011
Location: AustraliaPosts: 6487
| Posted: 10:47pm 20 Jun 2025 |
Thank Gerry, that should be useful.
I have a routine to read *.OPT files and there are 2 floats in the structure.
This is what I came up with:
CASE "float"
b1%= ASC(INPUT$(1,#3)) : b2%= ASC(INPUT$(1,#3)) :b3%= ASC(INPUT$(1,#3)) :b4%= ASC(INPUT$(1,#3))
tempint% = ((b4%*256+b3%)*256+b2%)*256+b1%
mantissa = tempint% AND &h7FFFFF
mantissa = mantissa +&h800000
exponent = (tempint% >>23)AND &hFF
exponent = exponent - 127
sign = (tempint% >>31)AND 1
tempfloat! = mantissa*2^-23*2^exponent * 10000 ' multiply by 10k to match OPTION LIST
IF sign THEN tempfloat!=0-tempfloat!
readdata$ = STR$(INT(tempfloat!))+" ("+STR$(b1%)+" "+STR$(b2%)+" "+STR$(b3%)+" "+STR$(b4%)+")"
b1%= ASC(INPUT$(1,#3)) : b2%= ASC(INPUT$(1,#3)) :b3%= ASC(INPUT$(1,#3)) :b4%= ASC(INPUT$(1,#3))
tempint% = ((b4%*256+b3%)*256+b2%)*256+b1%
mantissa = tempint% AND &h7FFFFF
mantissa = mantissa +&h800000
exponent = (tempint% >>23)AND &hFF
exponent = exponent - 127
sign = (tempint% >>31)AND 1
tempfloat! = mantissa*2^-23*2^exponent * 10000 ' multiply by 10k to match OPTION LIST
IF sign THEN tempfloat!=0-tempfloat!
readdata$ = STR$(INT(tempfloat!))+" ("+STR$(b1%)+" "+STR$(b2%)+" "+STR$(b3%)+" "+STR$(b4%)+")"
I didn't think of converting to 64bit at the bit level.
Jim