Before you can start using TurboEVD with the ShapeShifter, you have to make the following configuration changes. Start ShapeShifter and click the top-most button for graphics preferences. Select your type of display as external and type in path and name of the TurboEVD executable. Alternatively you can just use the file requester. Then go to the graphics mode selection and choose your preferred screen mode and size. Remember that the screen width must be an even multiple of 32 for usage with TurboEVD. Finally choose the refreshing rate and the amount of colours you want to use in Macintosh.
These two are the most important selections when considering the performance of the Macintosh emulation and the "snappyness" of its display. TurboEVD supports currently only 2, 4, 16 and 256 colour modes so selecting 15 or 24 bit true colour has no effect. Generally speaking the less colours, the faster the emulation is and feels like. Remember though that the screen mode you selected plays also a key role here. Multiscan and hires modes produce more DMA contention hence slowing CHIP ram speed. With TurboEVD you can usually leave the refreshing rate at one (1) because if there's no display changes TurboEVD doesn't practically use any time at all.
Here's a table which shows the CHIP mem speed in various screen modes as shown by the bustest.
Screen mode | Speed in megabytes per second |
PAL: Lores 320x256x2 | 6.2 MB/s |
PAL: Lores 320x256x256 | 5.2 MB/s |
DBLPAL: Lores 320x256x256 | 4.2 MB/s |
PAL: Hires Lace 640x512x2 | 6.2 MB/s |
PAL: Hires Lace 640x512x16 | 6.0 MB/s |
PAL: Hires Lace 640x512x256 | 4.3 MB/s |
Multiscan: Productivity 640x480x16 | 5.7 MB/s |
Multiscan: Productivity 640x480x256 | 2.1 MB/s |