The processor that initiated the revolution of the 1980s

Posted on March 28, 2010, 5:53 am

The MOS 6502 is a microprocessor with an 8-bit address bus of 16 bits, designed by Chuck Peddle in 1975. With the Z80, it sparked a series of computer projects that would eventually lead to the computer revolution of the 1980s. Despite the low clock speed of 1 MHz, the performance of 6502 was actually competitive with other processors using clock speeds higher in the late 1970s and early 1980s (the Zilog Z80, for example ). He scored only very little – a record 8-bit accumulator (A), two registers of 8 bit index (X and Y), a processor register 8-bit status (P), an 8-bit pointer stack (S), and a program counter 16-bit (PC) and a quite simple statement. The address of 16 bits, but is authorized to allocate up to 64 KB of memory. One of the first computers to use the 6502 was the Apple I (1976), the Apple II and Commodore PET, Atari computers and BBC Micro. The famous Commodore 64 used a MOS 6510, which was the successor of the 6502 with a digital I / O port and three buses of the state. The 6507, a simplified version of the 6502, has been used in the 2600 Atari video game console. The 8502 was a 2-MHz version of the 6502 which has been used in the Commodore 128. Millions of computer systems with MOS 6502 processor delivered over the 1980s. The MOS 6502 was very popular among programmers in assembly language (mostly because if its simplistic design), and later even 31 years it is now used to teach assembly language and architecture of the computer by many universities. Several companies have produced 16-bit derivatives of 6502, for example, the Western Design Center 65C816 (still widely used today) or (not entirely compatible) Mitsubishi 65,816. The report provided Synertek SY6516 was never released. 32-bit derivatives, including the West Design Center W65T32 terbium, a 6502 chip compatible with an address bus 32-bit, 16-bit data bus, and a variable length instruction set. The 6502 MOS has clearly dominated the homecomputer 8-bit and the video game world, but then Apple, Commodore and Atari all switched to the Motorola 68K architecture with their next generation 16-bit computers (the Macintosh, the Amiga and ST) . While the architecture in 6502 faded homecomputer the video game market, there is still a concept quite popular as it is still as the core chip microcontroller many today.