G Considering a disk with a number of tracks and each track has multiple sectors, we have a notation of a disk visit as (a, b), where a is the disk track number and b is the sector number on track a. For the following sequence of requests: (1, 23), (2, 57), (1,1), (1, 89), (2, 13), (2,78), (1,5), (2,75), (3, 45), (3,98), (2,72), (3,47), (2,76), (3,97). If you know this set of requests in advance, how would you reorder the sequence to minimize the total disk access time?

Write a new lc-3 trap subroutine (i.e. a subroutine that will be invoked via the trap instruction) that will receive a numeric digit entered at the keyboard (i.e. an ascii character), echo it to the screen, and return in r0 the corresponding numeric value: so if the user types the digit '7', the character '7' will appear on the screen, but the value returned in r0 will be b0000 0000 0000 0111 (#7) you may not use any trap calls in your code - you must implement the "polling" code that interrogates the keyboard status and data registers. ; getnum_tsr ; a subroutine for obtaining a numeric value ; given ascii numeric digit input to keyboard. ; the numeric digit is echoed to the console (e.g. '7' = b0000 0000 0011 0111), ; but the value returned in r0 is the actual numeric value ; corresponding to the digit (e.g. b0000 0000 0000 0111 =