this mode you can use maximum 2 colors in one attribute
cell. It means that you can set color of background, and
color of foreground (pixel color).
MultiColor mode generates the screen with resolution 160*200 pixels/16 colors. One pixel represents an area 2*1 pixels big. (it is fatter than hires pixel ;-)
The screen is divided into 40*25 attribute cells. Each attribute cell is 4*8 pixel big.
In this mode you can use maximum 4 colors in the attribute cell. Each pixel defined by 2 bites can have one of 4 different colors. One of colors is the background color.
MultiColor picture by Ollie/PRIDE
As you can
observe from today's competitions and demos, almost nobody
is able to paint nice pictures in this mode.
Here is the answer:
mode uses two MultiColor pictures (160*200/4 colors in
4*8 cell), each using its own attributes (except the color
RAM at $d800, which is shared by both).
These two MultiColor pictures alternates each frame, but one of them is shifted one point to the side. This causes visible effect of jerky movement from side to side. Fortunately, it also improves the fineness of C64 MultiColor mode, and gives painter larger color palette.
Flexible Line Interpretation mode generates same resolution as standard MultiColor mode - 160*200 pixels/16 colors.
This technique allows to use more collors in the attribute cell. It allows artist to use the full palette of 16 colors in each 4*8 pixel big attribute cell.
It's realized by a special routine, which by changing values in the VIC register $D011 causes that Bad Scan Line (In further text called Caroline*) is on each rasterline of visible screen.
For those who don't know what a
"Caroline" is: Caroline occur each 8th
rasterline. It's the time when the graphical processor
of C64 (VIC) is loading graphic data from memory.
Interlaced Flexible Line Interpretation is the connection of two greatest ideas in history of C64 graphic modes. MultiColor Interlaced mode (MCI), and Flexible Line Interpretation mode (FLI).
FLI generates 320*200 dots resolution using 6 colors in
each 8*1 points big attribute cell.
SuperHires Interlace - SHI
Super Hires can theoretically generate pictures in resolution of 96*200 pixels/16 colors. Though standard size of the pictures is only 96*167 pixels.
One 8*8 pixels big attribute area can contain 4 colors. 2 colors are same in the whole picture, and 2 can be set individually for each attribute area. (Background color, and foreground color, as in hires mode)
Realisation is quite simple:
Picture consists of 2 layers of multiplexed hires sprites. Hires sprite is 24*21 pixels big/1 color. Each layer consist of 4*8 hires sprites of the same color.
Two layers give us 2 colors, and Hires picture lying behind them give us another two, which can be set separately for each 8*8 pixels big attribute area.
Super Hires Interlace
generates pictures 96*200 pixels big.
I think than
now it's time to check the example picture.
Thanx To Jeffrey L. Jones for gramatical correctures.
*Caroline = Is a Dmagical new name for so-called BAD SCAN LINE. Wotnau and me spent a long time chatting about this line and decided to give her more appropriate name as we don't think that shereally is a bad line when she helped us and also other c64 dudez so many times. So we in DMAgic would like to tell you don't call our great line Bad Scan Line, she is not that bad!