isks was a significant issue in an entirely floppy-based system. The ability to make a "working backup" disk of vital application software was seen as important. Copy programs that advertised their ability to copy or even remove common protection schemes were a common category of utility software in this pre-DMCA era.
In another defining characteristic of the home computer, instead of a command line, the BASIC interpreter served double duty as a user interface. Coupled to a character-based screen or line editor, BASIC's file management commands could be entered in direct mode. In contrast to modern computers, home computers most often had their operating system (OS) stored in ROM chips. This made startup times very fast – no more than a few seconds – but made OS upgrades difficult or impossible without buying a new unit. Usually only the most severe bugs were fixed by issuing new ROMs to replace the old ones at the user's cost. Also, the small size and limited scope of home computer "operating systems" (really little more than what today would be called a kernel) left little room for bugs to hide.
Although modern operating systems include extensive programming libraries to ease development and promote standardization, home computer operating systems provided little support to application programs. Professionally written software often switched out the ROM based OS anyway to free the address space it occupied and maximize RAM capacity. This gave the program full control of the hardware and allowed the programmer to optimize performance for a specific task. Games would often turn off unused I/O ports, as well as the interrupts that served them. As multitasking was never common on home computers, this practice went largely unnoticed by users. Most software even lacked an exit command, requiring a reboot to use the system for something else.
In an enduring reflection of their early cassette-oriented nature, most home computers loaded their disk operating system (DOS) separately from the main OS. The DOS was only used for disk and file related commands and was not required to perform other computing functions. One exception was Commodore DOS, which was not loaded into the computer's main memory at all – Commodore disk drives contained a 6502 processor and ran DOS from internal ROM. While this gave Commodore systems some advanced capabilities – a utility program could sideload a disk copy routine onto the drive and return control to the user while the drive copied the disk on its own – it also made Commodore drives more expensive and difficult to clone.
Many home computers had a cartridge interface which accepted ROM-based software. This was also used for expansion or upgrades such as fast loaders. Application software on cartridge did exist, which loaded instantly and eliminated the need for disk swapping on single drive setups, but the vast majority of cartridges were games.
From the introduction of the IBM Personal Computer (ubiquitously known as the PC) in 1981, the market for computers meant for the corporate, business, and government sectors came to be dominated by the new machine and its MS-DOS operating system. Even basic PCs cost thousands of dollars and were far out of reach for typical home computerists. However, in the following years technological advances and improved manufacturing capabilities (mainly greater use of robotics and relocation of production plants to lower-wage locations in Asia) permitted several computer companies to offer lower-cost PC style machines that would become competitive with many 8-bit home-market pioneers like Radio Shack, Commodore, Atari, Texas Instruments, and Sinclair. PCs could never become as affordable as these because the same price-reducing measures were available to all computer makers. Furthermore, software and peripherals for PC style computers tended to cost more than those for 8-bit computers because of the anchoring effect caused by the pricey IBM PC. As well, PCs were inherently more expensive since they could not use the home TV set as a video display. Nonetheless, the