<P> Introduced at the 1965 New York Worlds Fair, the Programma 101 was a printing programmable calculator described in advertisements as a "desktop computer". It was manufactured by the Italian company Olivetti, and invented by the Italian engineer Pier Giorgio Perotto, inventor of the magnetic card system for program storage . </P> <P> The Soviet MIR series of computers was developed from 1965 to 1969 in a group headed by Victor Glushkov . It was designed as a relatively small - scale computer for use in engineering and scientific applications, and contained a hardware implementation of a high - level programming language . Another innovative feature for that time was the user interface combining a keyboard with a monitor and light pen for correcting texts and drawing on screen . In what was later to be called the Mother of All Demos, SRI researcher Douglas Engelbart in 1968 gave a preview of what would become the staples of daily working life in the 21st century: e-mail, hypertext, word processing, video conferencing, and the mouse . The demonstration required technical support staff and a mainframe time - sharing computer that were far too costly for individual business use at the time . </P> <P> By the early 1970s, people in academic or research institutions had the opportunity for single - person use of a computer system in interactive mode for extended durations, although these systems would still have been too expensive to be owned by a single person . Early personal computers‍--‌generally called microcomputers ‍--‌were often sold in a kit form and in limited volumes, and were of interest mostly to hobbyists and technicians . Minimal programming was done with toggle switches to enter instructions, and output was provided by front panel lamps . Practical use required adding peripherals such as keyboards, computer displays, disk drives, and printers . Micral N was the earliest commercial, non-kit microcomputer based on a microprocessor, the Intel 8008 . It was built starting in 1972, and few hundred units were sold . This had been preceded by the Datapoint 2200 in 1970, for which the Intel 8008 had been commissioned, though not accepted for use . The CPU design implemented in the Datapoint 2200 became the basis for x86 architecture used in the original IBM PC and its descendants . </P> <P> In 1973, the IBM Los Gatos Scientific Center developed a portable computer prototype called SCAMP (Special Computer APL Machine Portable) based on the IBM PALM processor with a Philips compact cassette drive, small CRT, and full function keyboard . SCAMP emulated an IBM 1130 minicomputer in order to run APL / 1130 . In 1973, APL was generally available only on mainframe computers, and most desktop sized microcomputers such as the Wang 2200 or HP 9800 offered only BASIC . Because SCAMP was the first to emulate APL / 1130 performance on a portable, single user computer, PC Magazine in 1983 designated SCAMP a "revolutionary concept" and "the world's first personal computer". This seminal, single user portable computer now resides in the Smithsonian Institution, Washington, D.C. . Successful demonstrations of the 1973 SCAMP prototype led to the IBM 5100 portable microcomputer launched in 1975 with the ability to be programmed in both APL and BASIC for engineers, analysts, statisticians, and other business problem - solvers . In the late 1960s such a machine would have been nearly as large as two desks and would have weighed about half a ton . </P>

Define the memory of a personal computer in terms of memory size types of memory and their purpose