Apple Computer Inc, preparing to extend its Macintosh product line in a couple of weeks, starts the New Year snowed under with demand for the various existing Macintosh models, and now has an estimated $250m backlog, reports Newsbytes. The company has expanded its manufacturing capacity and ran the assembly lines through the holidays, as well as leasing 168,000 square feet of additional space and converting its Apple II plant in Singapore to Macintosh production. The highly automated Fremont line is said to have capacity of 4,000 Macs and LaserWriters a day; 1988 Mac sales are thought to have exceeded 800,000, and Apple is forecasting 30% growth this year. On the product front, the company is expected to unveil the 16MHz 68030-based Macintosh SE/30 at the MacWorld Expo in San Francisco on January 20. The SE/30 is expected to feature the Superdrive floppy from the IIx that reads ProDOS, MS-DOS and OS/2 files as well as native ones, 2Mb or 4Mb and choice of 40Mb or 80Mb disk, but will likely cost nearer $5,000 than the $3,000 of the current SE. Key difference between the SE and the II is that the latter uses the high-speed Nubus. Apple may also unveil a slimmed down three-slot Mac IIx, and the machines are two of six new Macs due this year, another of which is the portable Mac, which won’t appear at the San Francisco bash, and may not arrive until late in the year. According to chairman John Sculley, the hold-up is the screen, which must be fast enough to keep up with rapid mouse movements, something beyond current liquid crystal displays. As a result, Apple wants an active matrix display, which are not yet out in volume. When it does arrive, the machine is expected to have 1Mb memory, 3.5 floppy, and 20Mb Winchester option.