How many registers does a 6502 have?
The 6502 has one main 8-bit accumulator register and two auxiliary 8-bit index registers called X and Y. The index registers are often used as array subscripts when referencing memory.
What is a 6502 assembler?
6502 assembly is a very low-level language that works specifically for the 6502 microprocessor — a very popular processor from the 1970s.
Does 6502 have memory?
Memory. The 6502 is an 8-bit processor with a 16-bit address bus. It is therefore able to access 64 kilobytes (216 bytes). Since each 16-bit address is comprised of two 8-bit bytes, memory can be viewed as 256 pages of 256 bytes each.
How does the 6502 perform stack operations?
The 6502 has hardware support for a stack implemented using a 256-byte array whose location is hardcoded at page $01 ($0100-$01FF), using the S register for a stack pointer.
How does the CPU stack work?
The stack is a list of data words. It uses the Last In First Out (LIFO) access method which is the most popular access method in most of the CPU. A register is used to store the address of the topmost element of the stack which is known as Stack pointer (SP).
Who made the 6502 processor?
6502 Micro-processor The geek was Steve Wozniak, the computer was the Apple I, and the chip was the 6502, an 8-bit microprocessor developed by MOS Technology.
How many registers are there in a 6502 microprocessor?
The 6502’s registers include one 8-bit accumulator register (A), two 8-bit index registers (X and Y), 7 processor status flag bits (P; from bit 7 to bit 0 these are the negative (N), overflow (V), reserved, break (B), decimal (D), interrupt disable (I), zero (Z) and carry (C) flag), an 8-bit stack pointer (S), and a 16-bit program counter (PC).
What is the MOS Technology 650x?
The MOS Technology 650X family represents a conscious attempt of eight former Motorola employees who worked on the development of the 6800 system to put out a part that would replace and outperform the 6800, yet undersell it.
What does 6502 stand for?
The MOS Technology 6502 (typically pronounced “sixty-five-oh-two” or “six-five-oh-two”) is an 8-bit microprocessor that was designed by a small team led by Chuck Peddle for MOS Technology.
Why is the ROR instruction not working on the 6502?
The earliest revisions of the 6502, such as those shipped with some KIM-1 computers, had a severe bug in the ROR (rotate right memory or accumulator) instruction. The operation of ROR in these chips is effectively an ASL (arithmetic shift left) instruction that does not affect the carry bit in the status register.
