Image Map Image Map
Page 1 of 2 12 LastLast
Results 1 to 10 of 19

Thread: More CRT woes: CTX 1451

  1. #1

    Default More CRT woes: CTX 1451

    So, I recently made a thread about my broken Trinitron, which I'm working to fix. As an interim, I picked up a free 14" CTX 1451 CRT to use in the meantime. However, I'm having issues with it. It works completely fine on my Linux laptop, displaying as 1024x768. However, when attached to my Dell Dimension (1999, on XP), it displays a horribly scrambled image. I've attached a photo to show what I mean.

    https://i.imgur.com/4qT3CR8.jpg

    The plug for the monitor is missing pins 9, 12, and 15. Could this cause a problem? What can I do to fix this issue? I've heard it is not plug and play, but should it not default to a 640x480 mode on this case? Ive done testing and found out it does both 1024x768 and 800x600 ok but it doesn't even give me the option to set 640x480 video. It does this both in Windows 10 and in Linux Mint as a secondary display, I only get the options for 1024 and 800. If I force my laptop to do 640x480 and have the CRT mirror, the issue comes back, so I assume it is an issue with displaying 640x480. What can I do to fix this?

  2. #2
    Join Date
    Oct 2008
    Location
    Kamloops, BC, Canada
    Posts
    4,783
    Blog Entries
    38

    Default

    The plug for the monitor is missing pins 9, 12, and 15. Could this cause a problem? What can I do to fix this issue?
    9 and 15 are normally not used anyways. Pin 12 is for an optional data pin so the OS can auto detect what resolutions and refresh rates are suitable for the monitor. A lot of the cheap monitors omitted it.

    It does this both in Windows 10 and in Linux Mint as a secondary display, I only get the options for 1024 and 800.
    In this day and age most operating systems will not give you the option to have a resolution that low because they assume you are not using a display that old, unless you go out of the way to force it. Additionally because of that missing data pin the OS can't probe the monitor and go "oh, you can actually do 640x480" so instead its giving you whatever the heck it thinks is a "Default" resolution but the refresh rate is wrong, hence the doubling.
    That being said, this statement is thrown out the window if it's still happening in DOS, at which point I guess the monitor actually only wants 800x600 or 1024x768 which makes absolutely no goddamn sense.
    Last edited by NeXT; September 30th, 2017 at 01:28 PM.
    = Excellent space heater

  3. #3
    Join Date
    Sep 2012
    Location
    Indiana, USA
    Posts
    345

    Default

    Since the CTX monitor doesn't communicate with the computer, the computer can't sense what resolution and refresh rate are compatible with it. The Computer is likely set for a video mode the monitor can't handle. Try connecting a monitor that works to the desktop and then setting the display properties for 640X480 at 60Hz, then reattach the CTX.

  4. #4

    Default

    Well, the problem is that once it reaches desktop it is ok displaying 1024x768, I am having issues in dos/while booting up where display properties have not yet come into effect. This is before Windows is loaded or anything else, although I also have problems when loading 640x480 games. I am indeed having this issue in dos or anything else. When I get off work I will experiment with my laptop and trying to force 640x480. I guess. I am just curious, why would a monitor be made that would not support the most default resolution for computers in the 90s? It seems odd, but maybe that is just me. Any more ideas for things to try?

  5. #5
    Join Date
    Apr 2015
    Location
    Austin, Texas
    Posts
    751

    Default

    Quote Originally Posted by username1 View Post
    why would a monitor be made that would not support the most default resolution for computers in the 90s?
    CTX is a junk monitor brand. I don't think I ever came across one of their monitors that worked properly, the most common failure on them was a shorting out flyback.

  6. #6

    Default

    Thanks for all the advice, is there anything I can do to squeeze 640x480 out of the thing? I'd hate to get rid of it as apart from this it's rock solid, quiet, and has a decent picture. But if 640x480 doesn't work I'll just have to, as I can't work without it. Any tips? It is an issue independent of windows, it simply doesn't correctly display a 640x480 signal from any source.

  7. #7
    Join Date
    Jan 2013
    Location
    Marietta, GA
    Posts
    2,077

    Default

    It seems more likely that the video card, even in DOS mode is defaulting to some higher refresh rate that is higher than this monitor can handle. The original graphics mode standard was 640*480 at 60hz. Any "VGA" monitor should be able to display that, but higher refresh rates were never really a rock-solid standard.

    Some older video cards came with DOS utilities that would let you set graphics mode refresh rates, that would automatically kick in when graphic DOS programs ran. (For VESA modes, there was UniRefresh). But that won't help much with XP.

    Some machines with integrated video may have even had monitor communication and refresh settings in the BIOS setup. If the video system in question is a motherboard integrated one, might check the BIOS for such settings.

    Exactly what video card(s) did you try?

  8. #8

    Default

    Currently I used my stock card, an ATI All-In-Wonder 9000. I have a few Diamond 32MBs, I may try those. I'll l
    try resetting the bios, maybe switching cards, and get back to you real quick

  9. #9

    Default

    My MS-DOS pc would default to 720x400 or something weird like that or that's what my Samsung widescreen monitor would say. Everything would look stretched (I even had it set to display the PC's native res without stretching) . Anyway using it with a 4:3 monitor had no issues.

  10. #10
    Join Date
    Jan 2013
    Location
    Marietta, GA
    Posts
    2,077

    Default

    720*400 (at 70hz, I think), is the resolution used by text mode, and should be supported by any "VGA" monitor. Of course your modern shortscreen monitors get all stupid about stretching stuff. That resolution is also used for pixel-doubled 320*200 modes. VGA monitors must also support 640*350 (again at 70hz, I think) to emulate high resolution EGA. 640*480 at 60hz is VGA graphics mode.

    I don't know about ATI cards, but I am aware that later Nvidia cards - later than the 6xxx series - will default to some much higher resolution (1280*1024?) and stretch text mode in to that. Not positive how they would behave with a basic VGA monitor, but I would expect it would barf. So later ATI cards like this one could very well be bumping up the resolution or refresh in a way that won't work with a basic VGA monitor.

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •