Apple Computer Inc is expected to launch its combination Mac and Windows machine as the Quadra 610 DOS Compatible at Comdex next week, MacWeek hears. The machine, code-named Houdini, includes the Apple Windows co-processor board and enables users to switch among the System 7, MS-DOS and Windows environments with a hot key. It is expected to include an 80486 processor and a VGA graphics chip, and comes plugged into the 68040 Processor Direct slot. It will use the screen, RAM, SCSI ports, serial ports and hard disk of the Quadra. Once the hot key is pressed, the Microsoft Corp environment takes over the screen; a second keystroke returns the user to the Mac System 7. The machine is not expected to support CD-ROM or networking in Windows or MS-DOS mode. It is expected to be offered in three configurations – a base one with 8Mb and 160Mb disk and floating point unit, the same thing with built-in Ethernet, and that with a 230Mb disk.