9128057f@levels.unisa.edu.au
Date: 11/28/92


Subject: A call for help - _again_ - with X!
From: 9128057f@levels.unisa.edu.au
Date: 28 Nov 1992 22:59:54 +1030

Greetings all ...

  Well, I posted a message a couple of weeks ago about problems running X and
got an absolute _zero_ response. Whether this was a problem with my news
server not spitting it out or with apathy within the group I don't know, but
what I do know is that if I don't get a response then I'll be forced into
dumping linux and X and switching to another os, such as o/s2. I just can't
accept a non-gui interface! So, a post of my problem follows - if anyone knows
of an answer or of somewhere to point me to i'd appriciate it. (and yes, i have
tried those "just run this to get your modes" programs, of which none worked
(obviously)) ...

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

  Ok, here's my problem: I ftp'ed down Linux from tsx-11 about a week ago
and set about installing it. I installed the complete base system including
compilers and X. The major problem that I am having now is with the Xconfig
file, mainly relating to monitor. I have determined that my graphics card
(an NT-200B, aka w/digital paradise) has clock rates of (at least) 25 and 28
mhz for 640x480x256. And so, I configured X with the pvga1 chipset, 640 480
virtual and 512k vram. This, for the moment, is fine for me. So, after a
while, it stopped complaining about my gfx setup. Great, or so I thought,
until I got to configuring the monitor ... <grimace> I tried the Vesa/ibm
standards for 640x480 in the different clock rates all to no avail, and I even
got to the stage of throwing in random changes to see if I would strike it
lucky (!) ... well, as you can see, I have failed.

  The monitor I'm using is a total peripherals TP250P multiscan monitor. Its
pretty cheap, but has the following specs:

  .29 dp
  horizontal sync: 30.5 to 36 khz
  vertical sync: 50 to 90 khz (automatically)

  max rez: 1024x768

  video band width : 40Mhz

  Active display area: 248mm (h) by 186mm (v)

  The manual also has a timing chart, and I tried feeding in what seemed like
near/similar values to those stated as "normal" but with no good result. It
gives a square wave like the following:
                       ____________ ________
     video: __________| |_______|

                   |C | D |E |
            ____ ___________________ _________
Horizontal: |__| |__|

                |B |
                | A |

                       ____________ ________
     video: __________| |_______|

                | Q | R |S|
            _ ____________________ ___________
  Vertical: |__| |__|

             |P |
             | O |

  Anyway, the ranges A,B,C,D,E and O,P,Q,R,S have the following listed times
- note that range 'D' lies between ranges 'C' and 'E', simillarly for 'R'.
(for 640x480 VGA, horiz. freq = 31.5khz, vert. freq = 60hz, -ve h & v sync
polarity):

        A: 31.78 (micro secs)
        B: 3.81
        C: 1.91
        D: 25.42
        E: 0.64

        O: 16.68 (milli secs?)
        P: 0.06
        Q: 1.05
        R: 15.25
        S: 0.32

  The display that I have managed to get ranges between a large smear on the
screen to a static (non completely unreadable) vertical image with the horiz.
part "ripped" across a few screens.

  If ANYONE can help me I'd be very gratefull!!! If any additional info is
required to help solve this, I can do my best! Reply via post or Email (please
use the @lux.levels account if possible) - many many thanks in advance! :-)

 Neil.