Atari Assembler Course - Quiz 3

Part I...
       Move a string upto 255 bytes long onto the screen display. Keep the
strings in .BYTE statements. Use the location SDLIST to find out
where the Display List is. The fourth and fifth entries in the
display list are the LO and HI pointers to the screen RAM. Make
use of indirect addressing in this routine so that it can move any
string with a specified size and starting location to any offset
within the screen RAM! Note that the Atascii string in the .BYTE
statement must be converted to the display code in order to go
directly to the screen RAM. (See page 59 in the Atari O/S user's
manual)

Part II...
  Using the above program as a subroutine, move three different
messages to different places on the screen depending on which of the
start,select or option keys is pressed. Also, check the BRKKEY
flag to stop the program if the break key is pressed.

PART III...
  Have the above program run during the deffered VBI except for the
BRKKEY check. The VBI routine should check once for a console key
then RTS when done. Make the main program simply set up the VBI
vector then BRK back to the DEBUG mode. Notice that the VBI is still
running along with the ASM/ED cart!