...The ability to do this is useful because a) it allows for tinkering far before physical implementation of the design is.
In addition to a strong core, WFCPK will also include modules emulating various processors (e.g., the MOS 6502 and the Zilog Z80) as well as the Video-Audio Interface (a custom VGA-compatible display and audio controller). The VAI is designed to fit within an FPGA to be integrated into real designs.
This library is licensed under the GPLv3 but also includes the classpath exception so that proprietary software can be linked against it required.
JBit is small java application for mobile phones (MIDlet) that gives you a programmable 8-bit microcomputer. With JBit, you can edit, save, run and debug assembly (6502) programs directly on your phone.
A microprocessor simulator for unit testing assembly code in embedded systems. Written in pure Java, it works with JUnit on any platform Java supports. Micros include 6502, 6800, 8051, Z80, and others.