| R/W | ADR | HEXADR | NAME | DESCRIPTION | OS |
|---|---|---|---|---|---|
| write only | 54277 | $D405 | VSCROL | Vertical Fine Scrolling | both |
If this location is set to a value other than zero, the ANTIC starts displaying every line with bit 5 set (enable vertical scrolling) that number of scan line "later", the picture is shifted "up".
VSCROL=0 VSCROL=2 ........ ..####.. ...##... .##..##. ..####.. .######. .##..##. .##..##. .######. .##..##. .##..##. ........ .##..##. ........ ........ .##..##. ........ .##..##. .##..##. .######. .##..##. .##..##. .######. .##..##. .##..##. .##..##. .##..##. ........ .##..##. ........ ........ ........
If there are several consecutive lines set for vertical fine scrolling (display list instruction with bit 5 set to "1"), the last line to be scrolled has to have bit 5 set to 0, to inhibit lines "jumping" into the screen.
see also: Display List topics, HSCROL
