ficiency and improve performance. However, at that time the manufacturing methods were not good enough to accomplish such a task. About 1960 photoprinting of conductive circuit boards to eliminate wiring became highly developed. Then it became possible to build resistors and capacitors into the circuitry by photographic means (Rogers, 142). In the 1970s entire assemblies, such as adders, shifting registers, and counters, became available on tiny chips of silicon. In the 1980s very large scale integration (VLSI), in which hundreds of thousands of transistors are placed on a single chip, became increasingly common. Many companies, some new to the computer field, introduced in the 1970s programmable minicomputers supplied with software packages. The size-reduction trend continued with the introduction of personal computers, which are programmable machines small enough and inexpensive enough to be purchased and used by individuals (Rogers, 153). One of the first of such machines was introduced in January 1975. Popular Electronics magazine provided plans that would allow any electronics wizard to build his own small, programmable computer for about $380 (Rose, 32). The computer was called the Altair 8800. Its programming involved pushing buttons and flipping switches on the front of the box. It didnt ...
