9507 Color Display Adjustments

© Copyright IBM Corp. 

9507 Color Display Parts 

 1  Display Panel
 2  Power-supply unit
 3  Cable-concentrator
 4  Lift/tilt/swivel stand

User Adjustable Effects
The two effects which are easiest to identify and adjust are 
     Vertically off-center image 
      Horizontally off-center image 

 Other effects are more subtle. In particular, liquid-crystal displays driven by an analog source exhibit certain optical effects which may, in some applications and workplace environments, over a period of time become distracting. 

 They are liable to be perceived by the user as: 
      Slight tremors up or down the vertical lines of tables, boxes and text characters, the tremors may seem to be moving or stationary. 
      A faint, linear, horizontal, background quiver in areas of solid color. 
      Slight ghost-imaging or smearing of horizontal lines. 

 They indicate that the optimum internal settings of the display panel installed by the factory need to be fine-tuned to the application or workplace lighting conditions. 

 However there are some colors which liquid- crystal displays cannot represent easily when driven by an analog source. The display creates these colors by switching alternate pels on and off, or half off. If you cannot get an acceptable rendering of a particular color, the user may have to choose another. 

 Non adjustable Effects 
 Liquid-crystal displays are liable to experience condition refereed to as failed sub-pixels. The user becomes aware of them as dark or bright  pinpoints which appear, in every application, at the same place, or places, on the screen. 

 You cannot adjust these pinpoints or remove them. The design specification for the IBM 9507 Color Display allows a small number of failed pixels, comprising a mix of on-pels and off-pels. 

 9507 Color Display Adjustment . 
 The Back-of Panel Controls. (Picture show factory-set positions) 

 Fine Tuning Procedure. 
   Only attempt to fine tuning when stable temperature conditions have been established for the IBM 9507 Color Display. This will generally mean that the display panel has been running for at least 20 minutes. 

A (Looks like R) 
A1(Looks like R1) 

© Copyright IBM Corp. 

   1. Open flap at back of display panel to reveal the fine tuning controls. 
   2. Ensure that the slide-switch A is set to Position 1, and all other switches are also at factory-set positions, as shown in the diagram. 
   3. Read the following notes before you continue. 
        Position 0 of slide-switch A, slide-switch D, and the recessed pushbutton A1, are for factory use. 
        The internal functions associated with rotary switch B are identified in 'The Back-of- Panel Controls' described below. 
        For each function selected with the rotary switch B pushbuttons B3 and B3 are used to effect a shift, in opposite directions, from the current internal settings. The shift in settings affects the characters on the screen. One press causes a one-increment shift in the value of setting. 
       The recessed pushbutton B1 is a RESET pushbutton. When it is pressed, the settings installed at the factory are re-installed. You may press pushbutton B1 (for example, with the tip of a pen) at any time during fine tuning  at any function selected with rotary switch B. 

Position 0 - factory use only.
Position 1 - enable user adjustment. 
Factory use only 
0 to adjust the clock-to-video phase relation.
2 to adjust the horizontal image centering.
3 to adjust the vertical image centering.
4 to adjust the max. white signal level.
Position 1 factory use only 
Reset all values to factory setup. 
Decrease value of function selected with rotary switch B. 
Increase value of function selected with rotary switch B.
Position 0 - For auto install of full-screen image at factory.
Position 1 - Expand or compress the image. 
Factory use only (set at position 0). 

From Peter 
   It really runs best in 16-colors VGA mode. Greyscales cause a lot "turbulences" on the display - running horizontal lines and such. Don't forget that the display is "analog attached": the signal from the video card is converted into analog signals and back to digital in the monitor. No comparison with modern large scale TFT LCDs, which have digital direct drive without the DA-AD conversion stage. 

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