why did the dragon only use green in most of its games?

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the888
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why did the dragon only use green in most of its games?

Post by the888 » Fri Jul 20, 2018 1:22 pm

hi,

i would like to know why the dragon only use green in most of its games? couldnt they have used black as the paper colour?

Sarah
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Re: why did the dragon only use green in most of its games?

Post by Sarah » Sun Jul 22, 2018 11:04 am

Game developers using "high resolution" graphics don't have a free choice of colours. They need to choose a fixed scheme, which includes a trade-off between the number of available colours and the screen resolution.

If a developer wishes to choose black and avoid green then the only possible option is a 2-colour scheme with just black & white; this does have the advantage of the best available graphics resolution (256x192) but sometimes the reduced colour palette can diminish the appeal of the game.

Therefore 4-colour schemes have often been used instead, which can only be used up to half the best available resolution, but can give a more vibrant visual result. There are only 2 choices of these 4-colour palettes; either the most popular option green, yellow, blue & red or the less commonly used option buff, magenta, cyan & orange.

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snarkhunter
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Re: why did the dragon only use green in most of its games?

Post by snarkhunter » Tue Jul 24, 2018 9:27 am

PMode3 games using a buff background looked rather awful most of the time ("Junior's Revenge" for instance). There is an exception, though. Not sure about the actual title, but it might be "Cosmic Crusader" (the 3D shooter featuring waves of ant-like aliens). The main screen is very readable and it uses a buff background.

The display and use of colours on "Lunar Rover Patrol" (PMode3 "green" set) was absolutely awesome.

sardine
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Re: why did the dragon only use green in most of its games?

Post by sardine » Tue Jul 24, 2018 9:11 pm

there was a couple of exceptions to the rule.

for example
hunchback loading screen from ocean... how was that done. looks like a mix of characters and graphics as it loads line by line not a normal text screen.

also the PD game FLEE(you had to type in from a dragon magazine or get on cassette through the mail) it was a pacman style game using custom character graphics. full colour not text.

I'm guessing some how it was a custom character MAP or something,,, very clever. I was amazed at all the colours on screen for a Dragon 32 and not the normal Green or Buff.
Flee-001.gif
Flee-001.gif (4.03 KiB) Viewed 1766 times
Hunchback_Screenshot01.png
Hunchback_Screenshot01.png (4.38 KiB) Viewed 1766 times

pser1
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Re: why did the dragon only use green in most of its games?

Post by pser1 » Tue Jul 24, 2018 9:22 pm

sardine wrote:there was a couple of exceptions to the rule.
for example
hunchback loading screen from ocean... how was that done. looks like a mix of characters and graphics as it loads line by line not a normal text screen.
Hi,
there are some games or screens like this one that are made using the semigraphics modes
Sometimes SG12 or SG24 upon the vertical definition you'll need
These modes allow use of normal text and 9 colors for a 'graphic' mode with a very low horizontal resolution: 64x96 or 64x192
in these mode each byte contains data about two pixels, so 32 bytes x2 = 64 pixels width (a bit too small)

cheers
pere

sixxie
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Re: why did the dragon only use green in most of its games?

Post by sixxie » Tue Jul 24, 2018 10:04 pm

Flee! uses SemiGraphics 6 (divided to be a 6K screen like regular SG24).

As SG6 also selects the EXTernal character set, and the data bus to the VDG is latched, it also ends up being used as character font data - this way you get a faux hi-res mode (with a limitation of bit 6 always being the same colour, as it also selecte INVert).

I've seen it written that this trick doesn't work on CoCos, but that may only be the ones that had a T1 fitted. AFAICT from early datasheets, data is latched to the VDG in the same way.

Just tried Flee! in MAME, and it seems to screw up the INVert line...

sardine
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Re: why did the dragon only use green in most of its games?

Post by sardine » Tue Jul 24, 2018 10:44 pm

I had the original tape and back in the early 80's it was a marvel to see a dragon game in colour with a black background as well as the loading screen for hunchback.

why didn't more software use these modes as they looked great.

also my next WOW! was the title screen music for shocktrooper more than one note much like Manic Miner which I was excited about as it looked and sounded like "V" aliens from the TV series :)

Alastair
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Re: why did the dragon only use green in most of its games?

Post by Alastair » Tue Jul 24, 2018 10:45 pm

Also of note is Dragonfire for the CoCo (I'm not sure if it was ever released for the Dragon) which manages to display both PMODE 3 palettes on one screen, thus giving an eight colour 128x192 picture.

sixxie
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Re: why did the dragon only use green in most of its games?

Post by sixxie » Tue Jul 24, 2018 10:47 pm

Well the awful horizontal resolution is the main reason! Some SG24 games are a bit unplayable because of it. But I do think Copta Snatch pulls it off!

sixxie
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Re: why did the dragon only use green in most of its games?

Post by sixxie » Tue Jul 24, 2018 10:52 pm

Yeah Dragonfire looks great. Someone on the list whose name escapes me for the moment did a PAL tweak and added a pretty excellent intro page.

Try DRAGFIR2.BIN from SJ’s file dump here http://roust-it.dk/coco/

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