titus-larsen-titus-1981-apple-interfacing

of the monitor screen each time the computer restarts the program.
This takes time, and it slows down the display. Can you suggest any
further changes to the program to reduce or eliminate the flicker
7
By removing the HOME command, you can reduce the time that
the Apple takes to clear the entire screen and "home" the cursor to
the upper left-hand corner of the video display area. When the
HT AB and VT AB commands are used, they position the cursor at
exactly the right place to print each ON or OFF on each line, one
bit. If no spaces are left after the "ON" at line 450, the printing
the ON would not cover the last F in OFF, and you would see
ONF, instead of ON. Thus, the spaces are needed to "erase" any
characters remaining on a line.
We suggest that you use the following for line 410 in your pro-
410 A = 128
Now, start the program by typing in HOME:GOTO 400, and then
pressing ENTER. If you do not use the HOME command, the program
will simply write over whatever is on the screen. The HOME
command clears the screen for you just before the program is started.
Step 8
The VT AB and HT AB commands can also be used to generate
titles or captions for each of the eight lines of information in the display.
Several captions follow, and you may add or change the ones
provided:
5 HOME
10 VTAB 8: HTAB l
15 PRINT "ACID PUMP";
20 VTAB 9: HTAB 1
25 PRINT "BASE PUMP";
30 VTAB 10: HTAB 1
35 PRINT "HEATER";
40 VTAB 11: HTAB l
45 PRINT "MIXER";
VTAB 12: HTAB 1
PRINT "FLUSH CYCLE";
60 VTAB 13: HTAB 1
50
55
65 PRINT "DISHWASHER";
70 VTAB 14: HTAB 1
1M