TITLE
    Quadra Series, Centris Series: Displays, Video Pinouts
Article ID:
Created:
Modified: 		9089
11/12/91
9/22/99
TOPIC

    This article details how to wire the video connector sense pins to access all the supported video modes of the Macintosh Quadra series and the Macintosh Centris series.

DISCUSSION

    The Macintosh Centris and Quadra frame buffer determines what type of display is attached to the video connector by examining the state of 3 sense line pins. The following chart details how these three pins must be wired for each of the supported display types. For each supported display, the screen resolution (horiz. pixels X vertical pixels), bandwidth, and the vertical and horizontal scan rates are listed.

    The Macintosh Quadra series and the Macintosh Centris series should support any display, whether from Apple or from another vendor, that meets one of the following specifications:

    STANDARD SENSE CODES:
    Display
    Sense pins
    10 7 4
    Hor x Vert
    (Pixels)
    Band Width
    (MHz)
    Vert
    Refrsh (Hz)
    Horiz
    Refrsh (KHz)
    Apple 21 Color
    0 0 0
    1152 x 870
    100
    75
    68.7
    Apple Portrait
    0 0 1
    640 x 870
    57.2832
    75
    68.9
    12" AppleColor RGB
    0 1 0
    512 x 384
    15.6672
    60.15
    24.48
    Apple 2-Page Mono.
    0 1 1
    1152 x 870
    100
    75
    68.7
    NTSC
    1 0 0
    underscan
    512 x 384
    12.2727
    59.94
    15.7
    1 0 0
    overscan
    640 x 480
    12.2727
    59.94
    15.7
    To produce a color NTSC signal, a RGB-to-NTSC converter is required.
    12" Apple High-Res
    Monochrome
    1 1 0
    640 x 480
    30.24
    66.7
    35.0
    13" AppleColor
    High-Res RGB
    1 1 0
    640 x 480
    30.24
    66.7
    35.0
    Apple 16" Color Disp.
    (See Note 4)
    832 x 624
    57.63
    75
    49.7
    Portrait Color,
    such as Radius
    1 0 1
    640 x 870
    57.2832
    75
    68.9

    NOTES:

    1. Sense pins 4, 7, and 10 are referred to as MON.ID1, MON.ID2, and MON.ID3 in the Macintosh Quadra pinout table or SENSE0, SENSE1, and SENSE2 in pinout tables for the video connectors.

    A sense pin value of 0 means that pin should be grounded to the C&VSYNC.GND signal; a value of 1 means do not connect the pin.

    2. Extended sense codes will be examined if the following sense code is detected: 1 1 1.

    3. The terms 'underscan' and 'overscan' are used to describe the active video resolution for NTSC and PAL modes. Underscan means that the active video area appears in a rectangle centered on the screen with a black surrounding area. This ensures that the entire active video area always is displayed on all monitors. Overscan utilizes the entire possible video area for NTSC or PAL. However, most monitors or televisions will cause some of this video to be lost beyond the edges of the display, so the entire image will not be seen.

    4) The Apple 16" Color Display should have pins 4 and 10 tied together and pin 7 should be unconnected. If used with a Macintosh Display Card, the Apple 16" Color Display also requires the Macintosh Display Card 4*8, 8*24, or 8*24 GC with revised ROMs.

    EXTENDED SENSE CODES:

    NOTE: For extended sense codes: Sense pin pair value of 0 means those pins should be tied together (as opposed to grounding 10, 7, or 4 to pin 11); value of 1, do not connect. DON'T wire any of these pins to ground.
    Display
    Sense pins
    4-10 10-7 7-4
    Hor x Vert
    Pixels
    Bandwidth
    (MHz)
    Refresh
    (Hz)
    Scan
    (KHz)
    16-inch Color, such as E-Machines
    0 1 1
    832 x 624
    57.2832
    75
    49.7
    PAL (1)
    PAL Option 1
    0 0 0
    underscan
    640 x 480
    14.75
    50
    15.625
    overscan
    768 x 576
    14.75
    50
    15.625
    PAL Option 2 (2)
    1 1 0
    underscan
    640 x 480
    14.75
    50
    15.625
    overscan
    768 x 576
    14.75
    50
    15.625
    VGA
    1 0 1
    640 x 480
    25.175
    59.95
    31.47
    Super VGA (3)
    1 0 1
    800 x 600
    36
    56
    35.16
    19" Color
    1 1 0
    1024 x 768
    80
    75
    60.24
    No external monitor (video halted)
    1 1 1

    NOTES:
    1. PAL has two wiring options, using the extended sense pin configuration. To produce a color PAL signal, an RGB-to-PAL converter is required.

    2. This sense code also requires a diode between sense pins 10 and 7, with anode towards pin 7, cathode towards pin 10.

    3. To enable Super VGA, after configuring and connecting the monitor for VGA, open the monitor's control panel and select Options. Choose Super VGA from the dialog and restart your system.

    4. The Macintosh Quadra 700 and 900 support PAL Option 1 at up to 8 bpp.

    5. The Macintosh Centris 610, 650, and Quadra 800 support PAL Option 1 at up to 16 bpp.

    6. The Macintosh Quadra 950 supports PAL Option 1 up to millions of colors.


    MACINTOSH QUADRA AND CENTRIS VIDEO PINOUTS:
    Pin
    Signal
    Description
    1
    RED.GND
    		Red Video Ground
    2
    RED.VID
    		Red Video
    3
    CYSNC~
    		Composite Sync
    4
    MON.ID1
    		Monitor ID, Bit 1 (also known as SENSE0)
    5
    GRN.VID
    		Green Video
    6
    GRN.GND
    		Green Video Ground
    7
    MON.ID2
    		Monitor ID, Bit 2 (also known as SENSE1)
    8
    NC
    		No Connection
    9
    BLU.VID
    		Blue Video
    10
    MON.ID3
    		Monitor ID, Bit 3 (also known as SENSE2)
    11
    C&VSYNC.GND
    		CSYNC & VSYNC Ground
    12
    VSYNC~
    		Vertical Sync
    13
    BLU.GND
    		Blue Video Ground
    14
    HSYNC.GND
    		HSYNC Ground
    15
    HSYNC~
    		Horizontal Sync
    Shell
    CHASSIS.GND
    		Chassis Ground

    If your monitor is a VGA type, try the following cable pinouts.

    A cable wired as follows may allow many different brands of VGA monitors to work on a Macintosh Quadra. We advise you to test the monitor on a Macintosh Quadra prior to purchase to see if it meets your expectations.

    Cable Pinouts:
    Macintosh Video
    DB-15
    Signal
    VGA Connector
    2
    Red Video
    1
    1
    Red Ground
    6
    9
    Blue Video
    3
    13
    Blue Ground
    8
    5
    Green Video
    2
    6
    Green Ground
    7
    15
    Hsync
    13
    12
    Vsync
    14
    14
    Sync Ground
    10
    10
    		Connect 10 and 7 so the sense pin ID will equal VGA.
    7

    There are a few issues to keep in mind with VGA monitors.

    * VGA monitors will vary depending on the vendor. Check with the vendor about Macintosh Centris and Quadra compatibility before buying, or better yet, actually try the monitor with a Centris or Quadra to see if it works and if the quality is acceptable.

    * Vendors have different image quality specifications. There may be significant differences between Apple monitors and the wide range of VGA monitors. Do a side-by-side comparison of the monitors you are considering before buying.

    * Many third party cable vendors have off-the-shelf cables that should work.


    MACINTOSH QUADRA TO NTSC VIDEO CABLE:
    Most NTSC devices use a RCA-type phono-connector and the following diagram uses that as a reference point. A cable wired as follows may allow many different brands of NTSC monitors to work on a Macintosh Centris or Quadra. We advise you to test the monitor on one of these machines prior to purchase to see if it meets your expectations.

    Adjust the phono-connector side to whatever type of connector is used (RCA, BNC, etc.). "Tip" is the pin in the center of the connector (the signal); the sleeve is the flange around the outer edges of the connector (the chassis ground).

    MACINTOSH QUADRA TO NTSC VIDEO CABLE EXAMPLE:
    Card Connector
    RCA-Type Phono-Connector
    4 MON.ID1 (sense0) - - - -|
    7 MON.ID2 (sense1) - - - -|
    11 C&VSYNC.GND - - - - - - |
    5 GRN.VID -----------------> Tip (signal)
    Shell CHASSIS.GND --------------> Sleeve (ground)

    Note: By grounding pin 4 and pin 7 to pin 11, the Macintosh Centris and Quadra CPUs are told that an interlaced (NTSC) monitor is attached. The actual black and white video signal is on pin 5 and connects to the center (Tip) of the phono-plug. The shell of the card connector connects to the sleeve of the phono-plug.

    To acquire a color NTSC signal from a Quadra (or any Apple Macintosh display card), an RGB-to-NTSC converter is required, such as those available from RasterOps, Truevision, and Computer Friends. We do not have the cable requirements for any of these interface devices.

Document Information
Product Area: Computers
Category: Macintosh Quadra & Centris
Sub Category: General Topics
Keywords:

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