provided for these devices. The initialization codes for each model of printer had to be written into the application. To use a program such as Wordstar with more than one printer (say, a fast dot-matrix printer or a slower but presentation-quality daisy wheel printer), a separate version of Wordstar had to be prepared, and one had to load the Wordstar version that corresponded to the printer selected (and exiting and reloading to change printers). Disk formats IBM System/34 and IBM 3740's single-density, single-sided format is CP/M's standard 8-inch floppy-disk format. No standard 5.25-inch CP/M disk format exists, with Kaypro, Morrow Designs, Osborne, and others each using their own. InfoWorld estimated in September 1981 that "about two dozen formats were popular enough that software creators had to consider them to reach the broadest possible market". JRT Pascal, for example, provided versions on 5.25-inch disk for North Star, Osborne, Apple, Heath hard sector and soft sector, and Superbrain, and one 8-inch version. Ellis Computing also offered its software for both Heath formats, and 16 other 5.25-inch formats including two different TRS-80 CP/M modifications. Certain disk formats were more popular than others. Most software was available in the Xerox 820 format, and other computers such as the Kaypro II were compatible with it. No single manufacturer, however, prevailed in the 5.25-inch era of CP/M use, and disk formats were often not portable between hardware manufacturers. A software manufacturer had to prepare a separate version of the program for each brand of hardware on which it was to run. With some manufacturers (Kaypro is an example), there was not even standardization across the company's different models. Because of this situation, disk format translation programs, which allowed a machine to read many different formats, became popular and reduced the confusion, as did programs like Kermit, which allowed transfer of data and programs from one machine to another using the serial ports that most CP/M machines had. Various formats were used depending on the characteristics of particular systems and to some degree the choices of the designers. CP/M supported options to control the size of reserved and directory areas on the disk, and the mapping between logical disk sectors (as seen by CP/M programs) and physical sectors as allocated on the disk. There were many ways to customize these parameters for every system but once they had been set, no standardized way existed for a system