MOS Technology 6502 and other 650x/651x processors are a family of
inexpensive 8-bit microprocessors.
6502 and 6512 processors could address 64KB of memory,
other CPUs in the family could address up to 8 KB. Stack size of the 6502
was limited to 256 bytes. The processors had only 6 registers, and
only one of these registers - an accumulator - could be used for
arithmetic and logic operations. The 6502 microprocessor had 13 addressing modes,
some of these modes made extensive use of two 8-bit index registers.
The processor didn't have I/O instructions, therefore 6502-based computers
used memory mapped I/O.
All microprocessors in the NMOS 6502/650x family
are software compatible between each other - the differences between
CPUs are in hardware (different maximum size of addressed memory,
clock oscillator is on-board or external, interrupt input options).
CMOS 65Cxx and 65SCxx microprocessors add new instructions and
addressing modes, and new hardware features such as memory lock
and bus enable signals. For more information please see
list of
differences between 65xx, 65Cxx and 65SCxx CPUs.
|
| Computers: | Apple I, Apple II series (except for Apple IIgs), Apple III, Atari 400, Atari 800,
Commodore PET 2001, Commodore 64, Commodore 128D (also had Z80), Acorn Microcomputer.
Franklin ACE 1200 (also had Z80), etc.
List of machines using 6502 CPU |
| Links: | The 6502 Microprocessor Resource |
|
| At a glance |
|---|
| Type: | | 8-bit microprocessor | | Introduction: | | 1975 | | Technology: | | NMOS, CMOS | | Frequency: | | 1 MHz - 14 MHz | |
.jpg)
.jpg)
.jpg)
