The program:
! Write a subroutine to clear the entire screen and
! fill it with an 80 by 24 grid of dots.
! Such a subroutine might be used in a
! computer graphics program.
! Test the program with i >= 3, j >= 5 first, do trace, slow (i,j)
! Set i >= 24, j >= 80
! Test the program with do trace, fast(i,j)
! For the subroutine:
! pseudocode:
! 1. clear the screen
! 2. write a line of dots
! 3. go to the next line
! 4. loop till through
! try the program for various lines and dots
LET lines = 24
LET dots = 80
CALL screen (lines,dots)
END
SUB screen (LINES,DOTS)
CLEAR
DO until i >= LINES
LET j= 0
DO until j >= DOTS !write a row of periods
LET j=j+1
PRINT ".";
LOOP
PRINT !go to the next line
LET i = i + 1
IF mod(i,2) > 0 then
SET COLOR "red"
ELSE
SET COLOR "blue"
END IF
LOOP
SOUND 1000 ,.1
END SUB
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