Virtual ][ versions

v6.5 [Mar 1, 2012]
- Fixed an issue where the Mockingboard card could halt the virtual machine (this happened, for example, in Ultima IV).
- Corrected an issue in the "floating bus" screen rendering, thereby improving compatibility.
- Fixed an issue that could cause stray pixels on the emulated screen when switching from 80-column text to low-resolution graphics.
- Improved screen rendering perfomance by using Apple's Grand Central Dispatch technology.