Long description

The 5 lines of code for figure (a) are as follows

copy underscore from underscore user open parenthesis buffer comma p comma count close parenthesis semicolon

enable underscore interrupts open close parenthesis semicolon

while open parenthesis asterisk printer underscore status underscore reg exclamation equals to READY close parenthesis semicolon

asterisk printer underscore data underscore register equals to p open box bracket 0 close box bracket semicolon

scheduler open close parenthesis semicolon

The 9 lines of code for figure (b) are as follow

if open parenthesis count equals to equals to 0 close parenthesis open curly bracket

unblock underscore user open close parenthesis semicolon

close curly bracket else open curly bracket

asterisk printer underscore data underscore register equals to p open box bracket i close box bracket

count equals to count minus 1 semicolon

i equals to i plus 1 semicolon

close curly bracket

acknowledge underscore interrupt open close parenthesis semicolon

return underscore from underscore interrupt open close parenthesis semicolon