Sync on Green FAQ


  1.10) 15" and 19" 1024x800 monitors

Following specifications apply to the 15" and 19" 1024x800 monitors:

Resolution  1024x800 (noninterlaced)

Scanning frequency range   Horizontal  50.2 kHz  (+/- 500Hz)
                           Vertical    47 to 80 Hz

Blanking time              Horozontal 4.713 usec maximum
                           Vertical   828.83 usec max  (15")
                                      831 usec max  (19")

Retrace time               Horozontal  3.713 usec max
                           Vertical    600 usec max

Video amplifier
  bandwidth = +/- 3dB form 50Hz to 70MHz minimum
  pulse rise and fall time = 5 nanosec (max) measured from 10% to 90%
  differential tilt = not more than 3% on blanking waveforms
  video polarity = Positive for Peak Luminance of the CRT
  video gain = no perceptible change at any brightness
               setting when a 15nsec pixel is written 
               adjacent to a 60nsec bar

  duration                 < 15 sec
  type                     Automatic at power on
  X-Ray radiation          < 0.5 MR/H

Horozontal frequency    Duration: 19.794 usec   (50.519 kHz)
           front porch             0.942 usec
           sync                    1.88 usec
           back porch              1.88 usec
           blanking                4.71 usec
           display area           15.084 usec
Vertical   frequency    Duration: 16.67 usec   (60.0 kHz)
           front porch            79.176 usec
           sync                   79.176 usec
           back porch            673.0 usec
           blanking              828.83 usec  (15")
                                 831.0 usec   (19")
           display area           15.841 usec (15")
                                  15.839 usec (19")
Note: Apollo 1024x800 color graphics boards use a horozontal frequency 
      of 50.519 kHz, vertical frequency of 60Hz
usec = microseconds

Chapter 2) B/W HP Monitors

  2.1) About the Author

Author: Mike Thomas
E-Mail: thomasm@agcs.com
Date: 15 Jul 1993

The black and white displays were built by PHILIPS in Canada. The plant there has been shut down, when I last enquired with Philips re: purchasing spare parts, I was informed that they did not want to support anymore new customers for this product line. Philips makes the new HP b/w monitors too, but it looks as if everything is manufactured in Taiwan.

The following is a list of technical info for the color and monochrome monitors, also includes information on common monchrome monitor repairs.

  2.2) Color Monitor CRT Specifications

Item         15 inch            19 in. (1024x800)    19 in. (1280x1024)
--------     -----------------  -------------------  ------------------
Size         16in. 15in.diag    20in. 19in.diag      20in. 19in.diag
Gun          Precision inline   Precision inline     Precision inline
Convergence  Self-convergence   Self-convergence     Self-convergence
Deflect ang  90 degrees         90 degrees           90 degrees
pitch        0.31 mm            0.32 mm              0.26 mm
Phosphor     Med persist P22    Med persist P22      Med persist P22
CRT Type     Matsushita         Matsushita           Matsushita J2P36X
             38JFG36X/B         48JFJ50X/B        
Yoke         Matsushita SST     Matsushita SST       Matsushita SST

    2.2.1) 1024x800 Color monitor performance specifications

Resolution 1024x800 noninterlaced

Scanning frequency range   Horiz  50.2 kHz +/-500Hz   
                           Vert   47 to 80 Hz

Blanking time  Horiz  4.713 usec max
               Vert   828.83 usec max (15")
                      831 usec max (19")

Retrace time  Horiz  3.713 usec max
              Vert   600 usec max

Video amplifier  Bandwidth          +/- 3 dB from 50 Hz to 70 MHz minimum
                 Pulse rise/fall    5 nanosecs max measured from 10%/90%
                 Differential tilt  Not more than 3% on blanking waveforms
                 Video polarity     Positive for Peak Lumiance of CRT
                 Video gain         No perceptable difference at any brightness
                                    setting when a 15-nano sec pixel is written
                                    adjacent to a 60-nano sec bar.<>

X-Ray radiation  Less than 0.5 MR/H

Horizontal Frequency duration 19.794 usec., Frequency = 50.519 kHz
Horizontal front porch - 0.942 usec.
Horizontal Sync - 1.88 usec.
Horizontal back porch - 1.88 usec.
Horizontal blanking - 4.71 usec.
Horizontal Display Area - 15.084 usec.

Vertical Frequency duration 16.67msec., Frequency = 60.0 Hz
Vertical front porch - 79.176 usec.
Vertical Sync - 79.176 usec.
Vertical back porch - 673.0 usec
Vertical blanking - 828.83 usec (15")
                    831 usec (19")
Vertical display area - 15.841 msec (15")
                        15.839 msec (19")

    2.2.2) 1280x1024 Color monitor performance specifications

Resolution - 1280 x 1024 noninterlaced

Scanning frequency range - Horizontal  73.7 kHz +/- 500 Hz
                           Vertical    68.24 Hz

Blanking time - Horizontal  3.328 usec max.
                Vertical    759.0 usec. max.

Retrace time  -  Horizontal  2.5 usec max
                 Vertical    395 usec max

Video amplifier - Bandwidth = +/- 3dB from 50 Hz to 170MHz
                  Pulse rise/fall = 2.7 nanosec. max measured from 10%/90%
                  Differntial tilt = Not more than 3% on blanking waveforms
                  Video gain linearity = Linear analog amplifier is capable
                                         of resolving a min. of 32 shades of
					 gray from black to white.

X-Ray radiation  -  Less than 0.5 MR/H

Pixel rate - 124.996 MHz
Pixel period - 8.000256 nsec.
Aspect Ration 5/4
Horizontally displayed pixels - 1280
Vertically displayed lines - 1024
Horizontal frequency - 73.702 kHz
Horizontal period - 13.568 usec., pixels 1696
Horizontal front porch - 0.256 usec., pixels 32
Horizontal sync - 1.536 usec., pixels 192
Horizontal back porch - 1.536 usec., pixels 192
Horizontal blanking - 3.328 usec., pixels 416
Horizontal display area - 10.240 usec., pixels 1280

Vertical fields per frame (noninterlaced) - 1
Vertical field frequency - 68.24 Hz
Vertical field period - 68.24 msec, lines 1080
Vertical front porch - 40.7 usec, lines 3
Vertical sync - 40.7 usec, lines 3
Vertical back porch - 678 usec., lines 50
Vertical blanking - 759 usec, lines 56
Vertical display area - 13.893 msec, lines 1024

    2.2.3) 19 inch Monochrome monitor specifications

Resolution - 1280 x 1024 noninterlaced

Active video time - Horizontal  10.857 usec.
                    Vertical    15.009 msec.

Blanking time - Horizontal  3.8 usec.
                Vertical    616 usec.

Front porch - Horizontal  407 nsec.
              Vertical    58.6 usec.

Back porch - Horizontal  1.9 usec
             Vertical    498 usec.

Sync pulse - Horizontal  1.49 usec.
             Vertical    58.6 usec.

Pixel time - 8.47 nsec.

Maximum light output - 30 +/- FLB

    2.2.4) Monochrome display cable pin outs

Pin 1 - ECL Video
Pin 2 - No connection
Pin 3 - Horizontal sync
Pin 4 - Vertical sync
Pin 5 - No connection
Pin 6 - ECL Video
Pin 7 - Video Shield
Pin 8 - Horizontal Sync Return
Pin 9 - Outer Shield Chassis

    2.2.5) DN2500 Monochrome monitor performance specifications

Resolution - 1280 x 1024 noninterlaced

Active video time - Horizontal  10.240 usec
                    Vertical    13.63 msec

Blanking time  -  Horizontal  3.072 usec
                  Vertical    639.0 usec
Front porch  -  Horizontal  0.256 usec
                Vertical    39.94 usec

Back porch  -  Horizontal  1.536 usec
               Vertical    559.0 usec

Sync pulse  -  Horizontal  1.280 usec
               Vertical    39.94 usec

Pixel time  -  8.00 nsec

Chapter 3) XFree modes for Apollo monitors

  3.1) About the Author

Subject: XFree modes for Apollo monitors
Author: Leonard N. Zubkoff
E-Mail: lnz@dandelion.com
Date: 22 Sep 1994

  3.2) Modes

The Apollo color 1280x1024 monitor is a Matsushita J2P36X. To drive it at 1280x1024 you'll need a dot clock of 125 MHz. If your VGA card won't do this, you may have to tear into the monitor's sweep circuitry, since it's not a multi-sync design.

Here are the timing numbers you'll need for your Xconfig file. If you get this to work, please send me your Xconfig.

There are actually two versions of this monitor, one with a 68Hz vertical refresh rate and the other with 70Hz. Here are Xconfig mode lines for both of them (these have been tested with my STB Pegasus VL):

# Apollo 010700-005 1280x1024 Color Display
"1280x1024-68" 124.996	1280 1312 1504 1696   1024 1027 1030 1080
"1280x1024-70" 124.996	1280 1312 1472 1664   1024 1027 1030 1072
In order to use one of these monitors with XFree86, you'll need a graphics card that supports the 125MHz pixel clock as well as providing RGB outputs with sync-on-green.

Very happily typing this on one of the 68Hz monitors...

Chapter 4) What's the difference between fixed frequency and multisynchronous monitors?

(Excerpts from comp.sys.ibm.pc.hardware.video FAQ)

(From Michael Scott and Bill Nott)

There are two primary measures of the maximum effective pixel addressability and refresh rate that a monitor is capable of. The maximum rate that a monitor can refresh the screen is measured in Hertz (cycles/second) and is called the vertical refresh rate (or vertical scan rate). The horizontal scan rate is the number of times that the monitor can move the electron beam horizontally across the screen, then back to the beginning of the next scan line in one second. Most early analog monitors were fixed frequency, meaning that they were intended to work only at one specific vertical refresh rate (often 60 Hz) and one horizontal rate (often this is expressed as a number of pixels, but this isn't really the same). Most older SUN, SGI and other workstation monitors were of this type. Generally, these monitors are limited in their applications, since they require that the incoming video signal falls within narrow timing specifications.

These type monitors also typically use composite video signals (with sync on Green), so are not compatible with most of today's PC graphics controllers. Also note that even if the composite video signal issue is overcome, there are additional issues related to attempting to use such monitors with a PC. Among these are DOS text mode support, and radiated emissions compliance. See "How can I get a fixed frequency (RGB) monitor to work on my PC?" below.

In part due to the desire to produce more flexible monitors (i.e. fewer different models), the lack of PC SVGA/EVGA/etc video standards, and in part due to recognition of an emerging trend toward higher pixel addressability formats within the computer industry, along with a desire to provide an upward migration path for new customers, vendors started to produce monitors capable of syncing to video signals within a range of frequencies. Such monitors are called multisychronous, or Multisync. Multisync is actually a trademark of NEC's, though it has become a generic term for a monitor which is capable of syncing to more than one video frequency. The meaning of multisynchronous has become somewhat muddled. To truly be multisynchronous, a monitor should be able to sync to any frequency of incoming video signal (within reason, of course). However, many so-called multisynchronous monitors can only sync to a number of discrete frequencies (usually 3 or 4).

If the video signal supplied to such a monitor is within the range of it's deflection circuits, the image will be displayed; otherwise, the image may be either not synchronized, or completely blanked. It is also possible to harm some monitors of this type by applying a video signal outside it's ranges, if protective measures were not put into place by the design. Thus, such a monitor will usually operate at the most common video modes, but may not operate at less common modes. This type of monitor may be referred to as a 'banded' design. A continuous frequency design should operate at any frequency within the specified range.

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