A computer interface to a line printer has seven data lines that control the movement of the paper and the print head and determine

which character to print. The data lines are labeled $A,B,C,D,E,F,$ and $G,$ and each represerts a binary $0$ or $1.$ When the dsta lines are

interpreted as a $7-$bit binary number with line A being the most significant bit, the data lines can represent the numbers D to ${127}_{10}-$ The

number ${13}_{10}$ is the command to retum the print head to the beginning of a line, the number $10$ means to advance the paper by one

line, and the numbers ${32}_{10}$ to ${127}_{10}$ represent printing characters.

$($a$)$ Write an equation for the variable $x$ which is $1$ if the data lines incirate a command to return the print head to the beginning of the

Iine.

$x=$

$($b$)$ Write an equation for the variable $Y$ which $i$ is if there is an advance paper command on the data lines.

$Y=$

$($c$)$ Write an equation for the variable $Z$ which is $1$ if the data lines inciaate a printable character. $($Hint: Consider the binary

representations of the numbers $0-31$ and $32-127$ and write the equation for $Z$ with only twa terms.$)$

$Z=$