Two decimal numbers, A and B$,$ are derived from your student ID $($SID$)$ number. A is

$(10)10$ plus the decimal number formed by the $4^{th}$ and $5^{th}$ digits of your SID number. B is

$(25)10$ plus the decimal number formed by the $6^{th}$ and $7^{th}$ digits of your SID number. For

example, if your SID number is $22373792$ A $,$ then A is $83$ and B is $104.$

Also, let $C=0-A=-$A and $D=0-B=-B.$ In the above example, C is $-83,D$ is $-104.$

use the following SID number to solve this question $21084996$ A

$($a$)$ By considering the stated binary representations, fill in the blanks in the Answer

section for part $($a$)$ below.

$($b$)[$Unsigned arithmetic$]$ Consider A and B in their $8-$bit unsigned binary form. Perform

the subtraction of $($i$)A-B,$ and $($ii$)B-$A using the method that takes $2$ s complement

operation at the subtrahend. Write your answer in $8-$bit binary form.

$($c$)[$Signed arithmetic$]$ Consider C and D in their $8-$bit signed $2$ s complement form.

Perform $($i$)C+D,$ and $($ii$)C-D$ using signed binary addition and signed binary

subtraction respectively. Indicate in each case whether an overflow has occurred. If

overflow does not occur, write down the answer in $8-$bit signed $2$ s complement format.

Answers for Ouestion $1$

Marks:

Fill in the values of A and B below.

$A=$

$,B=$

$($a$)8-$bit unsigned binary representation

Take $1$s complement on the $8-$bit unsigned binary representation

Take $2$s complement on the $8-$bit unsigned binary representation

$8-$bit signed magnitude representation

$8-$bit signed $2$ s complement representation