***6502 Microprocessor Memory Choice

 6502 microprocessor can use what brand of ram

The 6502 microprocessor itself is agnostic to the brand of RAM it uses. It can work with any compatible static RAM (SRAM) or dynamic RAM (DRAM) that meets its electrical and timing specifications. The key factors are:

    Voltage Levels: The RAM must operate at the same voltage levels as the 6502 (typically 5V for most versions).

    Timing: The RAM must be fast enough to meet the 6502's access time requirements. For example, a 1 MHz 6502 requires RAM with access times of less than 1 microsecond.

    Interface: The RAM must be compatible with the 6502's address and data bus interface.

Common RAM Brands and Chips Used with the 6502

In the 1970s and 1980s, many systems using the 6502 microprocessor used RAM chips from manufacturers such as:

    Intel: e.g., 2114 (1Kx4 SRAM), 2116 (16Kx1 DRAM)

    Motorola: e.g., MCM6810 (128x8 SRAM)

    Texas Instruments: e.g., TMS4116 (16Kx1 DRAM)

    Mostek: e.g., MK4116 (16Kx1 DRAM)

    Hitachi: e.g., HM6116 (2Kx8 SRAM)

    RCA: e.g., 2114 (1Kx4 SRAM)

Example Systems and Their RAM

    Apple II: Used 4116 DRAM chips (16Kx1) or similar.

    Commodore 64: Used 4164 DRAM chips (64Kx1).

    Atari 8-bit computers: Used 4116 or similar DRAM chips.

Modern RAM Options

For modern hobbyist projects, you can use newer SRAM chips like:

    Cypress CY7C199: 32Kx8 SRAM

    Alliance AS6C1008: 128Kx8 SRAM

These are often used in retrocomputing or DIY 6502-based systems due to their availability and ease of use.

In summary, the 6502 can use RAM from any brand as long as it meets the required electrical and timing specifications. The choice of RAM often depends on availability, cost, and the specific design of the system.