CompuServe Messages

Yes, 512 x 342 was the original Mac screen. You've probably seen the 640 x 400 number in reference to the portables. That's the resolution of the built-in screen of the Powerbooks. But I've never seen any stand-alone monitor for the Mac that was designed for 640 x 400. Apple makes a number of Mac monitors at assorted resolutions. I may be off a bit on some of these, but as I recall they are: 512 x 384 (12" color), 640 x 480 (12" monochrome, 13" color), 640 x 870 (15" portrait), 832 x 624 (16" color), 1152 x 870 (two page). And the aforementioned built-in 512 x 342 on the little Macs and 640 x 400 on the portables. Many other resolutions are available with third-party monitors. As I said, the Mac OS itself doesn't care what these numbers are. The bigger they are, the more it displays. Unlike the Amiga, the Mac really has only one video mode. It is based on 72 dpi – that is, 72 pixels on the screen represent one inch of printed output. So the bigger you make those "resolution" numbers, the more inches of a page you can see. That also means that if match large numbers with a small screen, everything will look small. Most manufacturers try to match the size of the screen to the number of dots so that 72 pixels on screen will actually be about an inch. The only other variable is bit depth. Depending on the video circuitry in a given Mac, you can pick various bit depths up to 24. Normally you'd probably just leave it set for the highest bit depth your video circuitry supports, but sometimes you want to run at a lower bit depth to increase the speed of screen redraws. ===Scott