conversion of negative numbers to octal/hex

[Sarikaa Bhatnagar]

Hi,

Can anyone please help me with the conversion of decimal -20 (negative 20) to octal and hexadecimal and vice versa.

Thanks,
Sarika.

[Henry Wong]

Originally posted by Sarikaa Bhatnagar:
Hi,

Can anyone please help me with the conversion of decimal -20 (negative 20) to octal and hexadecimal and vice versa.

Thanks,
Sarika.

Hmmm.... Interesting question. How would you do it?

Let's start with 20 in binary: (Somebody please check my math here!)

20 = 0000 0000 0001 0100

Go through 2's complement to find -20 in binary:

~20 = 1111 1111 1110 1011
~20 + 1 = -20 = 1111 1111 1110 1100

For Hexidecimal, just convert every group of 4 bits:

-20 = F F E C = 0xFFEC

For Octal, just convert every group of 3 bits:

-20 = 1 111 111 111 101 100
-20 = 1 7 7 7 5 4 = 0177754

Whew!! Hope I got my math right ...

Henry

[Sarikaa Bhatnagar]

Thanks a lot!!! I am really grateful.