Welcome, Guest. Please login or register.

Author Topic: MiniMig NTSC  (Read 13212 times)

Description:

0 Members and 1 Guest are viewing this topic.

Offline alexh

  • Hero Member
  • *****
  • Join Date: Apr 2005
  • Posts: 3644
    • Show all replies
    • http://thalion.atari.org
Re: MiniMig NTSC
« on: March 03, 2008, 10:02:15 PM »
Nice to see someone doing something at last.

Quote

freqmax wrote:
Source please :)

Yup. Under the terms of the MiniMig license yaqube, you've got to release the source code for all binary releases, even intermediate ones.

This is a good place to discuss MiniMig technical ideas

http://gamesource.groups.yahoo.com/group/minimigtg68/

Several individual people are all working towards ECS compatibility. RedskullDC has already released some mods to the blitter. Why not join together and share the work?
 

Offline alexh

  • Hero Member
  • *****
  • Join Date: Apr 2005
  • Posts: 3644
    • Show all replies
    • http://thalion.atari.org
Re: MiniMig NTSC
« Reply #1 on: March 03, 2008, 11:17:23 PM »
I dont think so.
 

Offline alexh

  • Hero Member
  • *****
  • Join Date: Apr 2005
  • Posts: 3644
    • Show all replies
    • http://thalion.atari.org
Re: MiniMig NTSC
« Reply #2 on: March 10, 2008, 11:10:46 PM »
Any news if this works? I dont see any source code :-)
 

Offline alexh

  • Hero Member
  • *****
  • Join Date: Apr 2005
  • Posts: 3644
    • Show all replies
    • http://thalion.atari.org
Re: MiniMig NTSC
« Reply #3 on: March 11, 2008, 09:14:33 AM »
Yes I believe so. Shame the author seems to have not returned here and not released the source.
 

Offline alexh

  • Hero Member
  • *****
  • Join Date: Apr 2005
  • Posts: 3644
    • Show all replies
    • http://thalion.atari.org
Re: MiniMig NTSC
« Reply #4 on: March 11, 2008, 04:10:40 PM »
Yes.

It makes MiniMig produces 60Hz, 31KHz (VGA) and so LCD panels which have a minimum vsync of 56Hz now work!

If you read the release, you see the option to use a 15KHz monitor (i.e. a TV) has been removed.
 

Offline alexh

  • Hero Member
  • *****
  • Join Date: Apr 2005
  • Posts: 3644
    • Show all replies
    • http://thalion.atari.org
Re: MiniMig NTSC
« Reply #5 on: March 11, 2008, 07:24:01 PM »
Unfortunately we dont know how he did it and so dunno what the impact is.
 

Offline alexh

  • Hero Member
  • *****
  • Join Date: Apr 2005
  • Posts: 3644
    • Show all replies
    • http://thalion.atari.org
Re: MiniMig NTSC
« Reply #6 on: March 11, 2008, 09:19:25 PM »
What is the interpolation like?
 

Offline alexh

  • Hero Member
  • *****
  • Join Date: Apr 2005
  • Posts: 3644
    • Show all replies
    • http://thalion.atari.org
Re: MiniMig NTSC
« Reply #7 on: March 12, 2008, 12:12:18 AM »
Quote

straycat wrote:
Hopefully yaqube might open the source for some good improvements  :-)

Not might. Has to. He's already broken the terms and conditions of the MiniMig GPL license by not releasing the source.
 

Offline alexh

  • Hero Member
  • *****
  • Join Date: Apr 2005
  • Posts: 3644
    • Show all replies
    • http://thalion.atari.org
Re: MiniMig NTSC
« Reply #8 on: March 12, 2008, 10:01:24 AM »
I think he will have just changed the constants that I mention  here:

http://www.opencircuits.com/Minimig_NTSC

He may have also changed the core clock rate of MiniMig to NTSC using a DCM but... I doubt it.

He may have changed lots of things as his goal is an ECS release.

It would be good to check the Agnus ID value, see if he changed it?
 

Offline alexh

  • Hero Member
  • *****
  • Join Date: Apr 2005
  • Posts: 3644
    • Show all replies
    • http://thalion.atari.org
Re: MiniMig NTSC
« Reply #9 on: March 18, 2008, 10:20:58 AM »
No, but once we have ECS no-one will care. They will all run PAL with the ability to switch to 60Hz in software.
 

Offline alexh

  • Hero Member
  • *****
  • Join Date: Apr 2005
  • Posts: 3644
    • Show all replies
    • http://thalion.atari.org
Re: MiniMig NTSC
« Reply #10 on: March 18, 2008, 05:11:57 PM »
Quote

alenppc wrote:
Yeah, although it would be nice to find a way of scaling down 50Hz games to a 60Hz screen, in order to run all of the PAL games one normally cannot run when using a regular TV set (not talking about 1084 monitors etc).

Scaling down? You mean scale down the extra lines that PAL screens have rather than loose the bottom of the picture? Not really possible without introducing black borders. It would contort the aspect ratio.

Quote

alenppc wrote:
How does this work on modern consoles? Unlike their retail counterparts, the Playstation/Xbox developement kit systems allow a PAL/NTSC software switch

The retail versions support PAL/NTSC software switch if hacked ;-)

Quote

alenppc wrote:
so the game is always scaled up/down to a different resolution without having to rewrite the software

Not true. Games written for 576@50Hz, but  run at 480@60Hz loose the bottom of picture. They are either written with black borders in PAL, or re-coded for NTSC.

Usually they are coded for 480@60Hz and just left with black borders at 576@50Hz

Quote

alenppc wrote:
How do they achieve this?

They don't.

Quote

alenppc wrote:
I'm pretty sure it's impossible to do with the Amiga implementation, but if anyone knows how other systems cope with this, that would be nice to know. :-)

With ECS you can switch from 576@50 to 480@60 but you'll loose the bottom of the picture, and some games coded specifically for 50Hz will screw up. Modern games consoles cannot be written to require specific VBL timing these days.
 

Offline alexh

  • Hero Member
  • *****
  • Join Date: Apr 2005
  • Posts: 3644
    • Show all replies
    • http://thalion.atari.org
Re: MiniMig NTSC
« Reply #11 on: March 19, 2008, 12:11:02 AM »
Quote

alenppc wrote:
And as far as the PS3 goes, you can't even do it, which is a shame - I've got loads of region free PAL DVDs which the stupid thing won't play so I have to rely on my old crappy 480p DVD player which does scale them down (albeit with some conversion artifacts).

Cant you use a linux software DVD player on PS3?
 

Offline alexh

  • Hero Member
  • *****
  • Join Date: Apr 2005
  • Posts: 3644
    • Show all replies
    • http://thalion.atari.org
Re: MiniMig NTSC
« Reply #12 on: April 08, 2008, 10:55:41 PM »
Quote

yaqube wrote:
@alehx: Are you working on adf write support?

I'm not doing anything right now.

ADF write support would require changes to the PIC C-code which relies on a time-limited demo of the High-tech PICC-18 commercial c-compiler.

I might try to see if it is easy to compile with a free compiler (if no-one has already done it).

Anyone know a particularly good free c-compiler for the PIC18 series? All I can find is this Student Edition Microchip C18.
 

Offline alexh

  • Hero Member
  • *****
  • Join Date: Apr 2005
  • Posts: 3644
    • Show all replies
    • http://thalion.atari.org
Re: MiniMig NTSC
« Reply #13 on: May 11, 2008, 01:45:36 PM »
Quote

Darrin wrote:
when the Minimig looks so good on the widescreen LCD.  :-)

MiniMig?? Widescreen? LCD? Looks good?? Surely not.

Stretched, scaled, distorted, looks bad is more what I would expect.
 

Offline alexh

  • Hero Member
  • *****
  • Join Date: Apr 2005
  • Posts: 3644
    • Show all replies
    • http://thalion.atari.org
Re: MiniMig NTSC
« Reply #14 on: May 11, 2008, 09:06:39 PM »
MiniMig isnt written in C, it's in Verilog HDL.

The PIC might be in C... but that has nothing to do with screen output.