I've never really thought about it before, or noticed, but does anyone know why Boulder Dash only used 4 colours despite being mode 0?
Was it originally intended to use mode 1?
Don't *know* why, but I can speculate. ;) For one thing it's an early multi-format game with near identical graphics to some other platforms with 4 colour low res screens, which is probably reason enough. Having a quick look just now I note it actually appears to have at least 5 colours - black, grey, white, orange and pink, so they're not exactly identical to other platforms. But a lot of the other colours are being used to achieve the rising dots animation effect on the tiles you see while the screen is building as well as the title screen, and also on the diamonds which despite using the same colours as the rest of the screen, are 'animated' with colour cycling, so use different inks.
Ugh you're right. I seem to remember it being a Mode 1 game just going by the colours but it is definitely chunky pixels.
To a lesser extent I often misremembered Super Robin Hood as likely being Mode 1 cos it's mostly just black, white, green and red (especially when playing with the background off) but then I remember the large image of Robin on the left of the screen has more colours and shades so it can't be Mode 1. Makes me wonder why the people sprites are so pale-skinned when the pinkish tone is right there on the large image.
Quote from: Carnivius on 10:35, 04 February 18
To a lesser extent I often misremembered Super Robin Hood as likely being Mode 1 cos it's mostly just black, white, green and red (especially when playing with the background off) but then I remember the large image of Robin on the left of the screen has more colours and shades so it can't be Mode 1. Makes me wonder why the people sprites are so pale-skinned when the pinkish tone is right there on the large image.
I suspect that may be to do with the Oliver Twin's Panda Sprites system that they used for many of their titles. It was clearly geared around making it quick to transfer graphics between systems (you can see this if you disassemble the CPC version of Dizzy, where objects have a "colour" that maps onto the Speccy version and these just get mangled into a 4-colour version on the CPC). That probably favour a three colour low-res sprite system, since that was a limitation on the C64's hardware sprites.
I had looked at Super Robin Hood a little while ago and saw what appeared to be a 'partial' dual playfield approach in use. The 'empty' backgrounds are 3 colours, black, dark green & grey, which are colours 0, 4 and 8. Sprites are white, red, and light green at 1,2 & 3. Those colours are repeated as shown in the screen below so simply xoring the sprites over the 3 background colours appears to mask them without having to use anything complex for background preservation. It's only when sprites cross other colours you get the usual xor colour changing, which perhaps explains the sparing use of other colours on anything sprites can cross.
Ah yes... Ink swapping would be the answer. That would explain the reduced colour palette if some of the inks are reserved to create the animation illusion. Well spotted and thanks.
I can now sleep easier tonight, lol.
Boulder Dash use 4 colors and wide pixels in old Arcade, Atari 8bit, C64, and BBC Micro too. So I guess they made it so, just to quick and easy convert graphics. :) Even sounds are the same.
http://www.mobygames.com/game/atari-8-bit/boulder-dash/screenshots (http://www.mobygames.com/game/atari-8-bit/boulder-dash/screenshots)