Write a function that dynamically allocates a block of memory and returns a charpointer to the block. the function should take an integer argument that is the amount of memory to be allocated. if the new operator cannot allocate the memory, the func-tion should return a null pointer.

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 =