You can allocate half of the total physical RAM in your Macintosh computer to the DOS Compatibility Card using shared memory. However, the only choices for how much memory can be shared are the choices in the menu of the PC Setup control panel: 2, 4, 8, 16, 32.

You cannot share Virtual Memory (VM) to the DOS Compatibility Card. For example, if the system only has 16 MB of physical RAM and you set VM to 32 MB, you can still only share a maximum of 8 MB of RAM.

There are two situations that must be kept in mind when sharing RAM between a Macintosh computer and DOS Compatibility Card:

• When changing the RAM allocation in the PC Setup control panel, you must restart the Macintosh before the RAM change takes effect.
• During startup, if you have several extensions or control panels that load before PC Setup, a reduced amount of RAM is available for the DOS Compatibility Card. For example, a large RAM Disk mounted at startup may allocate too much memory to itself before PC Setup loads. This will force PC Setup to reduce its memory allocation below the control panel setting. If this happens, you must evaluate whether all of your extensions and/or control panels are necessary, and turn off the unnecessary items.

[Previous] [Top] [Next]