APPLE has introduced a new Macintosh model capable of running both DOS and Apple operating systems. Is this model available in Hong Kong, and would you recommend it as a machine for people who would like to have the ''best of both worlds'', or for those who work with both systems on a daily basis? Also, does anyone in Hong Kong distribute Japanese Windows? K. C. CHAN Kowloon Apple did, indeed, launch such a machine, called the Quadra 610 DOS Compatible. It featured both a Motorola 68LC040 25-megaHertz (MHz) central processing unit and an Intel 486SX 25-MHz chip, the latter to allow it to run DOS applications. But this machine was never available in Hong Kong. According to an Apple spokesman, it was introduced in the United States in limited quantities since Apple was unsure how it would be accepted by the market. The system's success was satisfactory, so it may be re-released shortly, but this time based on PowerPC architecture. With the Quadra 610 DOS Compatible, users could switch from Mac to DOS or Windows operations at the touch of two keys. The system came pre-installed with MS-DOS 6.2 and shortly after it was announced at the autumn Comdex 1993 show it was awarded the ''Best System'' prize by BYTE magazine. Since the system was built with dual processors, users could run Mac and DOS or Windows applications in tandem, and even cut and paste information from one system to another. The system was built with eight MB of RAM and a 16-MB hard disk and was priced at US$1,579. The same hard disk was designed to run Mac, MS-DOS, or Windows applications. Apple also offered an optional CD-ROM drive designed to run Mac, DOS and Windows CD-ROMs. In addition, even DOS or Windows applications could print to any Mac-compatible printer attached to the system through its built-in serial port or optional Ethernet port. At the same time as it announced the Quadra 610 DOS compatible, Apple announced that a DOS Compatibility Card for both the Mac Quadra 610 and Mac Centris 610 systems was being made available for $399. This card, too, was a limited edition and not sold in Hong Kong. For more information on Apple's plans with this system, contact Apple directly on 506-8888. Microsoft did not have Japanese Windows in stock, a spokesman for the company said. You can, however, order a copy by calling Microsoft's customer services hotline on 804-4234. I HAVE heard that you can get portable drives for 128-MB optical disks, such as the ones made by the US company Pinnacle Micro. Is this true, and if so, who makes them and how can I get one? L. S. LO Hunghom Pinnacle Micro makes such a drive. Called the Pinnacle Tahoe, it is a portable 3.5-inch optical drive that comes with a rechargeable battery pack option and is perfect for high-storage-capacity portable computing. The battery-pack option allows for 31/2 hours of normal computer use. This feature can extend the run time of your computer's battery by eliminating the use of its on-board magnet or floppy drives. The Tahoe has an ultra-fast seek time and a rotation speed of 3,600 rpm, allowing for good data throughput. But if you use a PC notebook user, you are out of luck. Pinnacle Micro only has a version of the Tahoe for the Apple PowerBook. The Pinnacle Tahoe costs $999, with the battery pack and a travel case going for $199. For more information, call Pinnacle Micro in Irvine, California, on (714) 727-3300 or fax (714) 727-1913.