Chroma 81 - SCART and Colour interface for the ZX81

Discussions about Sinclair ZX80 and ZX81 Hardware
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nitrofurano
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Re: Chroma 81 - SCART and Colour interface for the ZX81

Post by nitrofurano » Wed Jan 03, 2018 8:43 pm

thanks! i’m going to try it asap!

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RobertK
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Re: Chroma 81 - SCART and Colour interface for the ZX81

Post by RobertK » Thu Jan 11, 2018 3:35 pm

Last night I made my first attempt to colourise a game using the Program Enhancement Creator, and I must say that I was surprised how easy and effective it was. Before I started I had no idea what exactly I had to do, and later that evening I enjoyed playing the game in full colour on my real ZX81 connected to my TV.

The game I chose was Space Raiders, which was a good choice as I later found out. This is what the game originally looks like:
SpaceRaiders.jpg
SpaceRaiders.jpg (16.97 KiB) Viewed 488 times

My intention was to loosely reproduce the look of the Spectrum version of that game:
SpaceRaiders_ZXSpectrum.gif
SpaceRaiders_ZXSpectrum.gif (2.84 KiB) Viewed 488 times

And here is the result (still WIP, but almost ready for release):
SpaceRaiders_Colourised.jpg
SpaceRaiders_Colourised.jpg (34.46 KiB) Viewed 488 times
The aliens were the difficult part, because some of their characters are used among different alien types, and one character can always have only one specific colour.

I made this alternative version...
SpaceRaiders_colourised_but_maybe_too_colourful.jpg
SpaceRaiders_colourised_but_maybe_too_colourful.jpg (34.67 KiB) Viewed 488 times
...but I rather prefer the first one, because this one is too colourful IMHO, remember that these are evil aliens that should not look too cheerful. ;-) But if most of you think that the second version is better then I could maybe change my mind.

If anyone is interested then I could elaborate what steps are required to colourise such a game, maybe I could write a little tutorial.

One more question: can any of you maybe patch the game to use cursor controls so that the Chroma joystick interface could be used?

Fruitcake
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Re: Chroma 81 - SCART and Colour interface for the ZX81

Post by Fruitcake » Fri Jan 12, 2018 12:42 am

Nice work! :D

I agree with you that the first version looks better. Have you tried making the blue and green characters forming the aliens the same colour, which would give their colouring full symmetry?

As requested, attached is a patched version of the game that uses the cursor keys.
spaceraiders(cursor_patched).zip
(2.35 KiB) Downloaded 18 times

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RobertK
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Re: Chroma 81 - SCART and Colour interface for the ZX81

Post by RobertK » Fri Jan 12, 2018 1:46 pm

Fruitcake wrote:
Fri Jan 12, 2018 12:42 am
Have you tried making the blue and green characters forming the aliens the same colour, which would give their colouring full symmetry?
We could of course make both "eyes" the same colour, but then we would have one colour less displayed on the screen. I thought that it won't look too disturbing in green and blue since these colours are "spectral neighbours".

To sum it up about the alien colours:
- what is white is white because of the two characters used for the base
- both "L" shapes should be the same colour for symmetry reasons, I chose red
- then there is the side part of the bottom alien row, I made this purple
- The yellow part of the top alien row makes a nice effect when a yellow bomb drops out of it
- and finally there are the "eyes" made of two different characters, so it was tempting to give them two so far unused colours...

I will send you my .col file so that you can try to further improve it and make the final version.
Fruitcake wrote:
Fri Jan 12, 2018 12:42 am
As requested, attached is a patched version of the game that uses the cursor keys.
Thanks! More games would deserve to be patched like that for Chroma users...
I assume that patching a game so that the original keys would still work as well would probably be too difficult, or even impossible?

Fruitcake
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Re: Chroma 81 - SCART and Colour interface for the ZX81

Post by Fruitcake » Fri Jan 12, 2018 3:03 pm

It sounds like you've put a lot of thought into the colours used and so I say run with it as you intend.

Attached is a new patched version of the game that supports both the standard control keys and the cursor control keys.
spaceraiders(standard_and_cursor_keys).zip
(2.4 KiB) Downloaded 17 times

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gammaray
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Re: Chroma 81 - SCART and Colour interface for the ZX81

Post by gammaray » Fri Jan 12, 2018 7:53 pm

Is Chroma compatible with the UDG characters using the UDG board by Andy, is it?

Vicious lie! I believe it was said not to work with ZXpand...

I will have to get one and try, I have been working on a compatibility chart.
Last edited by gammaray on Sat Jan 13, 2018 12:18 am, edited 1 time in total.
Finish what you start. Truth is over the mountaintop or six feet under.
4 x TS1000, 2 x TS1500 , 2 x timex 2040 printer, 1/2 x timex 2020 cassette deck, ZXPAND+AY, ZeddyNET, ZXBlast..., unfinished Spectrum...Still no life!

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gammaray
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Re: Chroma 81 - SCART and Colour interface for the ZX81

Post by gammaray » Fri Jan 12, 2018 7:54 pm

Maybe the eyes could be program to alternate color switching back and forth from green to blue. Hmm.
Finish what you start. Truth is over the mountaintop or six feet under.
4 x TS1000, 2 x TS1500 , 2 x timex 2040 printer, 1/2 x timex 2020 cassette deck, ZXPAND+AY, ZeddyNET, ZXBlast..., unfinished Spectrum...Still no life!

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RobertK
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Re: Chroma 81 - SCART and Colour interface for the ZX81

Post by RobertK » Fri Jan 12, 2018 9:06 pm

Ok, then I think we can call this finished and you may publish it on your web site if you want, together with your patched game file.
Fruitcake wrote:
Fri Jan 12, 2018 3:03 pm
Attached is a new patched version of the game that supports both the standard control keys and the cursor control keys.
spaceraiders(standard_and_cursor_keys).zip
Wow, thanks again, that makes it "downward compatible" to the instructions in the cassette inlay.

It's no big issue, but do you know why in the EightyOne emulator the PC's cursor keys worked with the previous version, but not with this one? Here both keys move the base to the left. It's no big problem as this seems to affect only the emulator.
gammaray wrote:
Fri Jan 12, 2018 7:54 pm
Maybe the eyes could be program to alternate color switching back and forth from green to blue. Hmm.
That would certainly look good, but it would go beyond Chroma's capabilities, which can only define a fixed colour set.

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mrtinb
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Re: Chroma 81 - SCART and Colour interface for the ZX81

Post by mrtinb » Fri Jan 12, 2018 9:30 pm

gammaray wrote:
Fri Jan 12, 2018 7:53 pm
Is Chroma compatible with the UDG characters using the UDG board by Andy, is it?
If I remember correctly Chroma implements UDG by itself.
Martin
ZX81, Lambda 8300, Commodore 64, Mac G4 Cube

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mrtinb
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Re: Chroma 81 - SCART and Colour interface for the ZX81

Post by mrtinb » Fri Jan 12, 2018 9:32 pm

Martin
ZX81, Lambda 8300, Commodore 64, Mac G4 Cube

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