Chroma 81 - SCART and Colour interface for the ZX81

Discussions about Sinclair ZX80 and ZX81 Hardware
Fruitcake
Posts: 147
Joined: Wed Sep 01, 2010 10:53 pm

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

Post by Fruitcake » Mon Nov 03, 2014 5:24 pm

I've had an enquiry about whether the Chroma interface will work with the Brazilian TK-85 clone. I don't own one of these and know very little about it. Does any one know how compatible this was with the ZX81? Does it use the same expansion bus signal layout?

User avatar
PokeMon
Posts: 2225
Joined: Sat Sep 17, 2011 6:48 pm

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

Post by PokeMon » Mon Nov 03, 2014 8:08 pm

I assume that kmurta has tested the interface on a TK85. 8-)
Maybe ask him to be sure but I am sure he has a TK85 to test with.

User avatar
kmurta
Posts: 147
Joined: Tue Sep 01, 2009 5:04 am
Location: Belo Horizonte - BR
Contact:

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

Post by kmurta » Mon Nov 03, 2014 11:36 pm

The screenshot for Galaxians shows a blue border but there was a bug in the JSZeddy emulator that swapped the blue and green bits of the border colour. When I try the game on real hardware the border appeared as green. I reported the bug in JSZeddy and it has now been fixed, but the Galaxians colourisation file will also need to be updated.
I found better to change the border color to black, see the update file in original post.

The cool thing is that if you don't like of the colors, the coloring can be easily customized. Just change the GalaxCol.asm file and compile it with TASM. ;-)
The CHR$128 mode is a nice clever extension to UDG mode and I have attempted to include logic to support it, but unfortunately there are not the resources available in the IC.
No problem, the games can be easily converted to QS Character Board.

By the way, I try to colorize a game that use the character 127 (CURSOR) as invisible mark, but in the JSZeddy the screen was corrupted when the char 127 is poked on Dfile in Color Mode. Is this a JSZeddy issue or Chroma really can't handle the CURSOR character in Dfile? I am attaching the game so you can check if it can run accurately at the Chroma81.

(The file was moved some posts below)
I've had an enquiry about whether the Chroma interface will work with the Brazilian TK-85 clone. I don't own one of these and know very little about it. Does any one know how compatible this was with the ZX81? Does it use the same expansion bus signal layout?
I assume that kmurta has tested the interface on a TK85. 8-)
Maybe ask him to be sure but I am sure he has a TK85 to test with.
No, I'm not (yet) a happy owner of Chroma81 ;)

The TK85 has the same expansion bus layout but presents some incompatibility in non standard modes like as pseudo-hires and wrx. Some TK85 units can handle pseudo-hires, others can not. With wrx all the units that i tested failed to show a stable display.
Last edited by kmurta on Wed Nov 05, 2014 4:01 pm, edited 1 time in total.
1 x ZX81, 2 x TK85 , 1 TK82C, 1 TK95, 1 x Ringo R470, 1 x Alphacom 32 printer, 1 x ZXpand
ZeXtender board, Joy81 - Programmable Joystick Controller, Turbo Sound 81
http://zx81.eu5.org

olofsen
Posts: 169
Joined: Wed Jan 08, 2014 12:29 pm

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

Post by olofsen » Tue Nov 04, 2014 2:10 am

By the way, I try to colorize a game that use the character 127 (CURSOR) as invisible mark, but in the JSZeddy the screen was corrupted when the char 127 is poked on Dfile in Color Mode. Is this a JSZeddy issue or Chroma really can't handle the CURSOR character in Dfile? I am attaching the game so you can check if it can run accurately at the Chroma81.
I think it is a bug - I'll have a look!

olofsen
Posts: 169
Joined: Wed Jan 08, 2014 12:29 pm

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

Post by olofsen » Tue Nov 04, 2014 4:00 am

I had never encountered this marker trick before! I hope the display is correct now. And is the emulation of the sound effects reasonable?

RWAP
Site Admin
Posts: 1315
Joined: Thu May 08, 2008 8:42 am
Location: Stoke-on-Trent, UK
Contact:

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

Post by RWAP » Tue Nov 04, 2014 11:24 am

I just think it's amazing how much better the games look with that splash of colour! :D

When will these be available on SellMyRetro?

User avatar
kmurta
Posts: 147
Joined: Tue Sep 01, 2009 5:04 am
Location: Belo Horizonte - BR
Contact:

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

Post by kmurta » Tue Nov 04, 2014 1:17 pm

olofsen wrote:I had never encountered this marker trick before!
It is used by missile AI routine to avoid them to target the destroyed cities.
olofsen wrote: I hope the display is correct now. And is the emulation of the sound effects reasonable?
Is better but was still not completely solved. Note that the characters at right of printed 127 char are moved to the left:
missil.png
missil.png (13.82 KiB) Viewed 2408 times
The sound effects are still not good here, there is an annoying buzzer following the sounds :(

See here (at 3:40min) the gameplay in a real machine: http://youtu.be/dKN2XfVRfx0?list=UUnxeu ... B72_zaGklg
1 x ZX81, 2 x TK85 , 1 TK82C, 1 TK95, 1 x Ringo R470, 1 x Alphacom 32 printer, 1 x ZXpand
ZeXtender board, Joy81 - Programmable Joystick Controller, Turbo Sound 81
http://zx81.eu5.org

olofsen
Posts: 169
Joined: Wed Jan 08, 2014 12:29 pm

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

Post by olofsen » Tue Nov 04, 2014 7:39 pm

Thanks for your comments - the issue with the characters at the right of printed 127 char that were moved to the left should now be solved, and sound should at least be improved :)

User avatar
kmurta
Posts: 147
Joined: Tue Sep 01, 2009 5:04 am
Location: Belo Horizonte - BR
Contact:

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

Post by kmurta » Wed Nov 05, 2014 3:57 pm

olofsen wrote:Thanks for your comments - the issue with the characters at the right of printed 127 char that were moved to the left should now be solved, and sound should at least be improved :)
Good news! Thank you!

Now the colorized Missile Command is working in JSZeddy :P

I would like to know if it works alright in a real ZX81 with Chroma interface.
missile.png
missile.png (15.88 KiB) Viewed 2357 times
Colorization file: https://sinclairzxworld.com/viewtopic.p ... 202#p31202
Last edited by kmurta on Wed Jun 20, 2018 9:49 pm, edited 1 time in total.
1 x ZX81, 2 x TK85 , 1 TK82C, 1 TK95, 1 x Ringo R470, 1 x Alphacom 32 printer, 1 x ZXpand
ZeXtender board, Joy81 - Programmable Joystick Controller, Turbo Sound 81
http://zx81.eu5.org

User avatar
stefano
Posts: 407
Joined: Tue Dec 11, 2012 9:24 am
Contact:

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

Post by stefano » Sat Nov 08, 2014 4:44 pm

Probably it is something I should have understood myself reading your posts and webpage carefully, but.. is there a way to use colors in WRX graphics mode ? 8-)

Post Reply