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Sync on Green FAQ

Contents:

[Document Version: 1.01] [Last Updated: 3/26/96]


Chapter 1) Sync on Green FAQ


  1.1) About the Author

Author: Dr. Jon Jenkins
E-Mail: jenkinsj@ozy.dec.com
Internal Version: 1.01


  1.2) Introduction

These files contain information to help people get Apollo RGB sync on G fixed frequency monitors to work with Xfree, It is important that your video card has a dot clock close enough to the speed the monitor expects. We have a number of monitors that expect 65 MHz clock, and most of our (very cheap) cards seem to be able to manage this. We have two monitors that expect 125MHz, they needed reasonable cards. The sample XF86Config file works for these cards with the hi-res monitor. See the file monitor-info for information about the various types of Apollo monitors. We have a circuit here to merge the G with the Hsync and Vsync of the VGA card, the R+,B+ go straight from the VGA output to the monitor. See the file Gsync.gif (TLJFILE!FOUND) for the circuit diagram, any electronics hack could make it on vero board in an hour. (all the usual flank covering disclaimers apply to the use of this circuit)

The console mode won't damage the monitor, but you can't read anything on screen. There is a program to give you a hires text mode, can't think of its name. We have our systems configured to run xdm so (if the sytem boots ok) you don't need the console.

This info courtesy of Javaan Chahl

(From the Editor)

Some of the last few sections come from the comp.sys.ibm.pc.hardware.video FAQ at URL: http://www.heartlab.rri.uwo.ca/vidfaq/videofaq.html (R)


  1.3) Notes on VGA->RGB conversion

I use stadard 74HC 14pin DIP gates available from any electronics store. I use a 14pin DIP socket originally so that I could change gate types (OR/XOR/AND) easily. 74HC86 (XOR) works just great with the VR320 (im using it now can also use OR, dont understand why ??).

The VN10KM is a small signal N channel enhancement mode mostfet also available from most electronics store.

IF the video card you are using is a standard VGA output: (Im using a diamond stealth 64 VRAM)


1: RED video
2: Green video
3: blue video
4: monitor id bit 2
5: Ground
6: red return
7: green return
8: blue return
9: NC
10: sync return
11: monitor id bit 0
12: monitor id bit 1
13: H sync
14: V sync
15: NC

I join all the "returns" together with the ground on the small PCB and use that as a common ground for the RGB cable to the monitor. You can use separate if you want to but you should join the green return and sync returns together. I did find some small shadowing if I didn't group them all together.

Just a note, when you set up your video card in Windows set it to 1280x1024x72|66 or whatever is closest I use a VR260 (1024x864) at 1027x768@66Hz (check with your manual DA or D4 are 72Hz) your VGA will not like this frequency so either disconnect it quickly or before you actually set the video card to this mode (i.e. put the OK as the active control in Windows and then connect the VR320 and hit return) My diamond setup gives me 10 seconds to do this adjustment When you exit you will probably have to select the 1280x1024 mode with your old VGA connected again and from then on every time you start Windows you will be able to view it in "big" colour mode. Note the vr320 will not work in DOS mode as it is not a multisync monitor so all you see when you boot up is garbage until Windows starts, I put "win" in my autoexec.bat file.

Note there is a danger here:

I had set up the monitor and for soeme reasonm it did not work so I couldn't see what was going on: my ol VGA wouldn't work and the VR wouldn't work either so I had to find the cards .ini files and edit by hand to get back to useable video!

For FreeBSD/XF86 the lines are:


#VR260 monitor is 70MHz 1024x864
#VR320/319 monitor is 130MHz 1280x1024
#
Modeline "1280x1024" 130.81 1280 1312 1472 1696 1024 1027 1030 1063 +hsync +vsync
Modeline "1024x864"   69.2 1024 1040 1168 1272 864 864 867 904 +hsync +vsync

The circuit to do this is as follows::

Notes:

  1. You may be dealing with 135MHz sqaure waves so there are lots of high frequency stuff around; use good RF practices.
  2. The coupling capacitors are a safeguard to start with I don't use them cause they caused shadowing around sharp colour changes (the ol RC effect).
  3. Use the XOR gate first as a test but you may need other gates to actually get it working
  4. A CRO will be handy for final adjustment.
  5. Make the device is as close as possible to the video outlet on the VGA card.
  6. Take the 5V from the PC power supply inside the box. I just hooked one of the spare connectors which I also use for an external fan (pentiums being the heaters they are!). Make sure (check it again!!) (and again!!!) you dont get the 12V one!!
  7. You must use a VN10KM or other: others will not work!


  1.4) Schematic 1

GIF Schematic (GIF87a, 17KB, width=880 height=688)


                        +5.0V
                        |
                        /
                        \ VR1 (1k carbon mini pot)
        33uF tantalum   |   ~0.3V DC in porch area
 GREEN------+----||-----+-----------------+-----GREEN to monitor
            |           |                 |
            +----||-----+                 |                       
        .1-.01uF ceramic                  |                              
                                          |
        gnd                               |
         |                                |
         /                                |
         \ 47k                            |                                
         /    |                          _|
 HSYNC---+----|-------\                  |     VN10KM or similar
              | GATE   |---CSYNC----+----||    small N channel
 VSYNC---+----|-------/             /    |_    enhancement MOSFET
         /    |                     \      |
         \                          /      |
         / 47k                      \ 47k  |
         |                          |      |
        gnd                        gnd    gnd

HSYNC, VSYNC and CSYNC are grounded with 47k carbon resisitors

GATE=LS or HC types, HC preferred.

OR: for -ve logic sync and no hsync during vsync
NAND: for +ve logic sync and no hsync during vsync
XOR: for -ve or +ve logic sync and hysnc during vsync

Capacitors are optional, I dont use them

use XOR gate with DEC monitors and as a first shot with others, then OR gate then NAND gate.

Get a CRO an adjust porch levels to 0.3V and 0 level (sync level) to 0.0V


  1.5) Voltages

(From Samuel M. Goldwasser)

Sync-on-green combines the H and V sync into a composite sync signal (your video card like ATI may already have this capability) and then merges it with the video.

Video: .7 V p-p white it positive.
Sync: .3 V p-p sync tips negative.

The combination is either OR or XOR - which works better depends on characteristics of video signal and monitor.


  1.6) XF86Config

Save this to a file:



Section "Files"
    FontPath "/usr/X386/lib/X11/fonts/misc/"
    FontPath "/usr/X386/lib/X11/fonts/75dpi/"
    FontPath "/usr/X386/lib/X11/fonts/100dpi/"
    RGBPath "/usr/X386/lib/X11/rgb"
EndSection

Section "ServerFlags"
EndSection

Section "Keyboard"
    Protocol "Standard"
    ServerNumLock
EndSection

Section "Pointer"
    Protocol "microsoft"
    Device "/dev/ttyS1"
EndSection

# Monitor configuration for Apollo monitors - 010700-001 19" 1280x1024 68Hz
# Use with care!! Do not use this configuration for other monitors

Section "Monitor"
    Identifier "Mag"
    VendorName "buggers"
    ModelName "15"
    BandWidth 100	# EDIT THIS!
    HorizSync 20-90	# EDIT THIS!
    VertRefresh 45-100	# EDIT THIS!
    ModeLine "Apollo" 125 1280 1312 1504 1696  1024 1027 1030 1080
EndSection

Section "Device"
    Identifier "Diamond Stealth 64 DRAM (Trio64)"
    VendorName "buggers"
    BoardName "unknown"
    VideoRam 2048
    Option "dac_8_bit"
EndSection

Section "Screen"
    Driver "accel"
    Device "Diamond Stealth 64 DRAM (Trio64)"
    Monitor "Mag"

    Subsection "Display"
	Depth 8
	Modes "Apollo"
        ViewPort 0 0
        Virtual 1280 1024
    EndSubsection

EndSection

#### Apollo FAQ - monitors info


  1.7) About the Author

Subject: Apollo FAQ - monitors info
Author: Russell Ayling
E-Mail: rayling@pandc.rta.oz.au

I compiled this info a while ago from an HP source plus bits and pieces I picked up. There are frequent questions about the monitors (esp. frequency) so maybe this, or part of it, could go in the FAQ. (I've mailed this out many times already, it would be easier to just refer people to the FAQ.)


Russell Ayling                    |  Internet : rayling@xwdev.pandc.rta.oz.au
Roads and Traffic Authority       |  Phone    : + 61 2 218 6945
260 Elizabeth Street              |  FAX      : + 61 2 218 6099
Surry Hills, NSW, AUSTRALIA 2010  | 


  1.8) Colour Apollo monitors


Part numbers:
 
007284R     15" 1024x800 60Hz
 
008398-001R 19" 1024x800 Northern hemisphere
008398-005R 19" 1024x800 Southern hemisphere
 
010700-001R 19" 1280x1024 68Hz Northern hemisphere
010700-004R 19" 1280x1024 68Hz Southern hemisphere
010700-005R 19" 1280x1024 70Hz Northern hemisphere
010700-006R 19" 1280x1024 70Hz Southern hemisphere

Note: 1280x1024 "F" graphics cards support 68Hz and 70Hz by jumper selection. (A 70Hz monitor will run at 68Hz, but the image will be slightly narrower than the screen display limits.)


             15" 1024x800       19" 1024x800      19" 1280x1024
             --------------     ------------      -----------------
Size         16"                20"               20"
             (15" diagonal      (19" d.m.)        (19" d.m.)
                  measure)
                                       
CRT type     Matsushita         Matsushita        Matsushita
             38JFG36X/B         48JFJ50X/B        J2P36X
 
Dot trio
pitch        0.31mm             0.32mm            0.26mm
 
Phosphor     Medium             Medium            Medium short
             persistance P22    persistance P22   persistance P22
 
Electron gun:     Precision inline
Convergence:      Self convergence
Deflection angle: 90 degrees
Deflection yoke:  Matsushita Type SST


  1.9) 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
Degauss
  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 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
 
Part numbers:
 
007284R     15" 1024x800 60Hz
 
008398-001R 19" 1024x800 Northern hemisphere
008398-005R 19" 1024x800 Southern hemisphere
 
010700-001R 19" 1280x1024 68Hz Northern hemisphere
010700-004R 19" 1280x1024 68Hz Southern hemisphere
010700-005R 19" 1280x1024 70Hz Northern hemisphere
010700-006R 19" 1280x1024 70Hz Southern hemisphere

Note: 1280x1024 "F" graphics cards support 68Hz and 70Hz by jumper selection. (A 70Hz monitor will run at 68Hz, but the image will be slightly narrower than the screen display limits.)


             15" 1024x800       19" 1024x800      19" 1280x1024
             --------------     ------------      -----------------
Size         16"                20"               20"
             (15" diagonal      (19" d.m.)        (19" d.m.)
                  measure)

CRT type     Matsushita         Matsushita        Matsushita
             38JFG36X/B         48JFJ50X/B        J2P36X

Dot trio
pitch        0.31mm             0.32mm            0.26mm

Phosphor     Medium             Medium            Medium short
             persistance P22    persistance P22   persistance P22

Electron gun:     Precision inline
Convergence:      Self convergence
Deflection angle: 90 degrees
Deflection yoke:  Matsushita Type SST


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