Close! FF 07 is -249. This is pretty close to zero on a 15 bit scale which means reasonably close to quiet. By 15-bit scale, I mean 15-bits of positive numbers and 15-bits of negative numbers. The top bit is “sign".

> I am confused as to how it is changed to signed.

The sign bit (most significant bit) is a 1 (negative) so that requires a bit more work.

Answer: 2’s compliment the data to find out how negative it is. How far is the value away from 0.

1) Reverse all the bits. FF 07 becomes 00F8.

2) Add 1. 00F8 + 1 = 00F9

3) Convert to decimal. F = 15. 15*16 = 240. 240 + 9 = 249

4) Change the sign. -249

As a kind of pain in the neck, the programmers mode on the Windows calculator on my machine doesn’t seem to have a setting to tell it how many bits are in the registers. (yes it does - it defaults to 64-bit size so FF07 is considered positive). Screen shots to change calculations to 16-bit size in next comment.

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