The c64's graphic capabilities are even more complex than what Rob correctly has pointed out (very well done btw!). I've played around with those in the 80's and early 90's as I have done some of those side scrolling colourful demos with a little piece of music underneath myself.
Hires Mode
Is a screen with a 320x200 pixels@16 colors resolution consisting of 40x25 attribute cells.
Each attribute cell is 8x8 pixels big. In this mode you can use maximum 2 colours in one attribute cell.
It means that you can separately set the colour of background, and the colour of foreground (pixel colour).
It's very much like CGA in the early PCs. This screen mode resembles the spectrum screen but has a higher resolution. There are games that 'emulate this graphics mode' by the use of the text based mode with adapted character sets that is actually displayed at 320x200 resolution. There's a lot of c64 ports to spectrum games using this like the spectrum does, only the spectrum did it faster.
I've used this graphics mode with nmi-sprites on top (raster interrupt sprites to be able to display more than 8 sprites at once) to be able to simulate 320x200 pixels with 4 colours per 8x8 pixel attribute cells. Those sprites needed to be single colour/hires sprites in order for it to work. Multicoloured sprites had a horizontal resolution that was half the 320x200 resolution.
Multicolour Mode
Is a screen with half the resolution 160x200 pixels@16 colours. One pixel consisting of an area 2x1 pixels big. The pixels actually have doubled in horizontal size! The screen consists of 40x25 attribute cells with each attribute cell being 4*8 pixels big. In this mode a maximum of 4 colours per the attribute cell can be used. Each pixel is defined by 2 bytes and can have one of 4 different colours, with one of the colours being the background colour. Most c64 games use this mode with hires or multicoloured sprites.
Most c64 games use this mode with hires or multicoloured sprites.
I got this from the programmer's reference guide. But this website explains it much better than I do and shows some nice examples of enhanced graphics modes on the c64 that programmers have discovered and that where not thought possible by the original designers of the machine. The graphics modes consists of various interlaced modes being able to use more colours per attribute cell, simulate more than 16 colours by blending or interlacing. I just love the c64 because of the direct access to the hardware we were able to tap into possibilities the original designers didn't foresee to be possible!
Hires Mode
Is a screen with a 320x200 pixels@16 colors resolution consisting of 40x25 attribute cells.
Each attribute cell is 8x8 pixels big. In this mode you can use maximum 2 colours in one attribute cell.
It means that you can separately set the colour of background, and the colour of foreground (pixel colour).
It's very much like CGA in the early PCs. This screen mode resembles the spectrum screen but has a higher resolution. There are games that 'emulate this graphics mode' by the use of the text based mode with adapted character sets that is actually displayed at 320x200 resolution. There's a lot of c64 ports to spectrum games using this like the spectrum does, only the spectrum did it faster.
I've used this graphics mode with nmi-sprites on top (raster interrupt sprites to be able to display more than 8 sprites at once) to be able to simulate 320x200 pixels with 4 colours per 8x8 pixel attribute cells. Those sprites needed to be single colour/hires sprites in order for it to work. Multicoloured sprites had a horizontal resolution that was half the 320x200 resolution.
Multicolour Mode
Is a screen with half the resolution 160x200 pixels@16 colours. One pixel consisting of an area 2x1 pixels big. The pixels actually have doubled in horizontal size! The screen consists of 40x25 attribute cells with each attribute cell being 4*8 pixels big. In this mode a maximum of 4 colours per the attribute cell can be used. Each pixel is defined by 2 bytes and can have one of 4 different colours, with one of the colours being the background colour. Most c64 games use this mode with hires or multicoloured sprites.
Most c64 games use this mode with hires or multicoloured sprites.
I got this from the programmer's reference guide. But this website explains it much better than I do and shows some nice examples of enhanced graphics modes on the c64 that programmers have discovered and that where not thought possible by the original designers of the machine. The graphics modes consists of various interlaced modes being able to use more colours per attribute cell, simulate more than 16 colours by blending or interlacing. I just love the c64 because of the direct access to the hardware we were able to tap into possibilities the original designers didn't foresee to be possible!
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