* Connection as shown wil allow multiple resolutions up to 1152x870. Reverse diode to limit resolutions to 1024x768. The Mac Centris, Quadra, and later systems frame buffer determines what type of display is attached to the video connector by examining the state of 3 sense line pins.
The Mac Quadras, Centris series, and later models should support any display, whether from Apple or from another vendor, that meets one of the following specifications:
STANDARD SENSE CODES (1 or more of the sense pins grounded):
| Display | Sense Pins | Horiz & Vert | Band Width |
Vert Refrsh |
Horiz Refrsh |
||
| 10 | 7 | 4 | Pixels | (MHz) | (Hz) | (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 (To produce a color NTSC signal, an RGB-to-NTSC converter is required.) | 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 | |
| 13 Apple Hi-Res Mono | 1 | 1 | 0 | 640 x 480 | 30.24 | 66.7 | 35.0 |
| 13 AppleColor Hi-Res RGB |
1 | 1 | 0 | 640 x 480 | 30.24 | 66.7 | 35.0 |
| Apple 16 Color Disp. | 832 x 624 | 57.63 | 75 | 75 | |||
| Portrait Color, such as Radius |
1 | 0 | 1 | 640 x 870 | 57.2832 | 75 | 68.9 |
| EXTENDED SENSE CODES (enabled by not grounding any sense pins) | |||||||
| Sense Pins | |||||||
| 10-7 | 7-4 | ||||||
| 16 color, such as E-Machines |
0 | 1 | 1 | 832 x 624 | 57.2832 | 75 | 49,7 |
| PAL: PAL has two wiring options, using the extended sense pin configuration. To produce a color PAL signal, an RGB-to-PAL converter is required. | |||||||
| 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 | 1 | 1* | 0 | underscan-640 x 480 | 14.75 | 50 | 15.625 |
| overscan- 768 x 576 | 14.75 | 50 | 15.625 | ||||
| (*Note: This PAL option also requires a diode between pins 10 and 7, with the cathode on 10) | |||||||
| VGA | 1 | 0 | 1 | 640 x 480 | 25.175 | 59.95 | 31.47 |
| Super VGA | 1 | 0 | 1 | 800 x 600 | 36 | 56 | 35.16 |
| (To enable Super VGA after configuring the sense pins and connecting the monitor for VGA, open the Monitors control panel and select Options. Choose Super VGA from the list and restart your system.) | |||||||
| 19 color | 1 | 1 | 0 | 1024 x 768 | 80 | 75 | 60.24 |
| No external monitor (video halted) |
1 | 1 | 1 | ||||
Notes:
1) Sense pins 4, 7, and 10 are referred to as MON.ID1, MON.ID2, and MON.ID3 in the Macintosh 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 (pin 11); 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 (no sense pins grounded).
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 means leave open. DONT wire any of these pins to ground.
correct
incorrect