TITLE
    Power Macintosh 7500/8500: Maximum Color Depths
Article ID:
Created:
Modified:
18358
8/10/95
9/29/97

TOPIC

    The Power Macintosh 7500 and 8500 series computers come with 2 MB of VRAM, expandable to 4 MB. The 7500 and 8500 have 4 VRAM DIMM slots (2 in use and 2 available). VRAM DIMMs must be installed 2 at a time. A VRAM upgrade can be accomplished via two third party 1 MB VRAM DIMMs.


DISCUSSION

    The Power Macintosh 7500 and 8500 series computers have a fast 64-bit data path to VRAM. Both can also support display resolutions of up to 1,280 by 1,024 pixels with 24-bit color of up to 1,152 by 870-pixel resolution.

    DIMMs must be 32-bit-wide, 112-pin fast-paged mode with 70ns RAM access time or faster. Do not use the 256K or 512K VRAM SIMMs used in older Macintosh computers.

    If your Power Macintosh 8500 computer is equipped with 2 MB of VRAM, you can switch between a monitor and a television, but you cannot view the desktop on both at the same time. For more information regarding video out to television, please refer to page 58 of the "Power Macintosh 8500 Series User's Guide".

    The following table defines the maximum color depths available for a given resolution and memory size. Lower color depths are supported down to 8 bit or 256 colors. This is the same information that is reproduced in the guide that comes with each computer -- "Technical Information: Specifications for Power Macintosh 7500 series computers."


    Note: The maximum visible number of colors is millions. In the past, Apple has also labeled millions as 24 bit color. On AV and Power Macintosh computers, 24 bit or 32 bit can be used interchangeably to mean support for millions of colors. In some literature, you may see 32 bit shown in place of 24 bit or millions. Think of this as 24 plus 8: 24 bit for displaying millions of colors plus 8 bit for special uses, such as alpha channel support (transparency, masking, opaque and tranlucent information) and chroma key support.


    |-----------------|-------|----------|-----------|----------|-------------|
    |                 |       |          | 2 MB VRAM |4 MB VRAM |Refresh rates|
    |                 |       |          |  maximum**| maximum**|----|--------|
    |     Monitor     |  VIS* |Resolution|   colors  |  colors  |Vert| Horiz  |
    |                 |       |          |           |          |(Hz)| (kHz)  |
    |-----------------|-------|----------|-----------|----------|----|--------|
    | 12" RGB         |  N/A  |  512x384 | millions  | millions | 60 | 24.48  |

    |-----------------|-------|----------|-----------|----------|----|--------|
    | 12" Monochrome  |  N/A  |  640x480 |    256    |   256    | 67 | 34.971 |
    |-----------------|-------|----------|-----------|----------|----|--------|
    | 13" RGB Hi-Res  |  N/A  |  640x480 | millions  | millions | 67 | 34.971 |
    |-----------------|-------|----------|-----------|----------|----|--------|
    | 14" RGB Hi-Res  | 11.5" |  640x480 | millions  | millions | 67 | 34.971 |
    |-----------------|-------|----------|-----------|----------|----|--------|
    | VGA             |  ***  |  640x480 | millions  | millions | 60 | 31.505 |
    |                 |       |  800x600 | millions  | millions | 60 | 39.921 |
    |                 |       |  800x600 | millions  | millions | 72 | 48.1   |
    |                 |       |  800x600 | millions  | millions | 75 | 47.933 |
    |                 |       | 1024x768 | thousands | millions | 60 | 48.294 |
    |                 |       | 1024x768 | thousands | millions | 72 | 58.286 |
    |                 |       | 1024x768 | thousands | millions | 75 | 60.093 |

    |-----------------|-------|----------|-----------|----------|----|--------|
    | Full-page       |       |          |           |          |    |        |
    |    Monochrome   |  N/A  |  640x870 |    256    |   256    | 75 | 68.773 |
    |-----------------|-------|----------|-----------|----------|----|--------|
    | Full-page RGB   |  ***  |  640x870 | thousands | millions | 75 | 68.773 |
    |-----------------|-------|----------|-----------|----------|----|--------|
    | 14" AudioVision | 11.5" |  640x480 | millions  | millions | 67 | 35     |
    |-----------------|-------|----------|-----------|----------|----|--------|
    | 16" color       | 14.8" |  832x624 | millions  | millions | 75 | 49.670 |
    |-----------------|-------|----------|-----------|----------|----|--------|
    | 19" color       |  ***  | 1024x768 | thousands | millions | 75 | 60.060 |
    |-----------------|-------|----------|-----------|----------|----|--------|
    | Two-page        |       |          |           |          |    |        |
    |    Monochrome   |  N/A  | 1152x870 |    256    |   256    | 75 | 68.476 |

    |-----------------|-------|----------|-----------|----------|----|--------|
    | Two-page RGB    | 11.5" | 1152x870 | thousands | millions | 75 | 68.476 |
    |-----------------|-------|----------|-----------|----------|----|--------|
    | Multiple        | 13.3" |  640x480 | millions  | millions | 67 | 34.971 |
    |    Scan 15      |       |  832x624 | millions  | millions | 75 | 49.670 |
    |-----------------|-------|----------|-----------|----------|----|--------|
    | Multiple        | 16.1" |  640x480 | millions  | millions | 67 | 34.971 |
    |    Scan 17      |       |  832x624 | millions  | millions | 75 | 49.670 |
    |                 |       | 1024x768 | thousands | millions | 75 | 60.060 |
    |-----------------|-------|----------|-----------|----------|----|--------|
    | Multiple        | 19.1" |  640x480 | millions  | millions | 67 | 34.971 |
    |    Scan 20      |       |  832x624 | millions  | millions | 75 | 49.670 |
    |                 |       | 1024x768 | thousands | millions | 75 | 60.060 |
    |                 |       | 1152x870 | thousands | millions | 75 | 68.476 |

    |                 |       |1280x1024 |    256    | thousands| 75 | 79.964 |
    |-----------------|-------|----------|-----------|----------|----|--------|

    * Viewable Image Size
    ** 256=image depth of 8 bits (bpp), thousands=image depth of 16 bits
    (bpp), millions=image depth of 32 bits (bpp).
    *** Refer to the manual that came with your monitor to determine VIS.
    N/A not available


Document Information
Product Area: Computers
Category: Power Macintosh
Sub Category: Power Macintosh 7500; Power Macintosh 8500

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