Video Output On The Machines
Reading a value from, or writing any value to, certain memory addresses controlled so called "soft switches". The value read or written does not matter, what counts is the access itself. This allowed the user to do many different things including displaying the graphics screen (any type) without erasing it, displaying the text screen, clearing the last key pressed, or accessing different memory banks. For example, one could switch from mixed graphics and text to an all-graphics display by accessing location 0xC052 (49234). Then, to go back to mixed graphics and text, one would access 0xC053 (49235).
Read more about this topic: Apple II Graphics
Famous quotes containing the words video, output and/or machines:
“We attempt to remember our collective American childhood, the way it was, but what we often remember is a combination of real past, pieces reshaped by bitterness and love, and, of course, the video past—the portrayals of family life on such television programs as “Leave it to Beaver” and “Father Knows Best” and all the rest.”
—Richard Louv (20th century)
“Lizzie Borden took an axe
And gave her mother forty whacks;
When she saw what she had done,
She gave her father forty-one.”
—Anonymous. Late 19th century ballad.
The quatrain refers to the famous case of Lizzie Borden, tried for the murder of her father and stepmother on Aug. 4, 1892, in Fall River, Massachusetts. Though she was found innocent, there were many who contested the verdict, occasioning a prodigious output of articles and books, including, most recently, Frank Spiering’s Lizzie (1985)
“The machines that are first invented to perform any particular movement are always the most complex, and succeeding artists generally discover that, with fewer wheels, with fewer principles of motion, than had originally been employed, the same effects may be more easily produced. The first systems, in the same manner, are always the most complex.”
—Adam Smith (1723–1790)