Path: utzoo!attcan!uunet!ogicse!zephyr.ens.tek.com!vice!bobb
From: bobb@vice.ICO.TEK.COM (Bob Beauchaine)
Newsgroups: comp.sys.tandy
Subject: Re: How to get 16 colors out of a TGA . . . ?
Keywords: CGA, RGB, Monitors
Message-ID: <5899@vice.ICO.TEK.COM>
Date: 27 Sep 90 22:00:22 GMT
References: <27095@boulder.Colorado.EDU>
Distribution: na
Organization: Tektronx Inc., Beaverton, Or.
Lines: 35

In article <27095@boulder.Colorado.EDU> mdperry@boulder.colorado.edu (Marc D. Perry) writes:
>I have a Tandy 1000TX which has the standard Tandy Graphics Adaptor.
>Everything I have read implies (no, states) that the TGA can display
>up to 16 different colors at simple resolution (is that 320 x 200, or
>something?, I forget).  I have mine plugged into an Amdek RGB monitor
>(circa 1985), and have only ever seen 8 colors; both in programs that
>allow you to select the foreground/background colors, and in that
>basic color program that comes in IBM-DOS.
>

  I have the same configuration as you, except my monitor is also a 
  Tandy.  I don't think your monitor is the problem; the monitor only
  displays the RGB signals from the graphics card, and I'm pretty sure
  any standard CGA monitor will suffice.

  The problem is software.  The 320x200,16 color mode is IBM video mode
  10 (I think, no reference on my desk).  This is a *graphics only* mode,
  first introduced on the PC Jr.  This mode is almost unused in
  commercial software, with one large exception : games.  You will see on
  most game packages a note claiming that the game supports Tandy graphics.
  This almost always means the game will display 16 colors.  From your 
  post, I think you are trying to get 16 colors in text mode.  
  
  This is
  possible on any standard CGA card, but requires you to manipulate the
  intensity/blink bit in one of the video ports.  You could do so from 
  the command line, but any program that resets the video mode will 
  probably only allow 8 colors again.

  Only one programming platform supports this video mode: BASIC.  None
  of the compilers from Microsoft or Borland have internal support for
  this mode (or the 640x200x4 colors mode, either). Very discouraging.

  Bob Beauchaine
  bobb@vice.ICO.TEK.COM