6502-NOP

This is a simple ROM for the A.C. Wright 6502 project filled with NOPs ($EA) that does nothing (NOP = No Operation).

Prerequisites

Install cc65 Toolchain

The cc65 toolchain provides the assembler and linker needed to build 6502 assembly code.

macOS (using Homebrew):

brew install cc65

Linux (Debian/Ubuntu):

sudo apt-get install cc65

Other platforms: See cc65 documentation

Optional: Install minipro (for EEPROM burning)

Only required if you plan to program an AT28C256 EEPROM chip:

brew install minipro

Building

Build the ROM image:

make

This generates:

• NOP.bin - 32KB ROM image ($8000-$FFFF) filled with NOP instructions ($EA)
• NOP.lst - Assembly listing file for debugging

Verification

View the generated binary as hex dump:

make view

You should see a file filled with ea bytes (the NOP opcode).

Programming EEPROM

To burn the ROM to an AT28C256 EEPROM chip using a TL866 programmer:

make eeprom

Note: This requires a TL866 (or compatible) programmer and the minipro software.

Cleaning Build Artifacts

Remove generated files:

make clean