P65 Assembler 0.7.2

The P65 assemblers are assemblers for the 6502 microprocessor (such as is used in the Commodore 64, Apple II, and Nintendo Entertainment System).
They are designed to be able to support a wide variety of output formats, both to support multiple target platforms and to produce code for emulators.
The eventual goal of P65 is to be as expressive as the more powerful assemblers of the late 80s, such as DASM. Its not there yet, but its getting there.
Main features:
- Highly portable - All versions of P65 are written in portable scripting languages. The original releases were done in Perl. While P65-Perl 1.1 is stable and reasonably powerful, it lacks some major features, such as modules and macros. P65-Ophis, the Python port, will run on slightly fewer architectures, but will still run on all current major systems.
- Flexible output format - P65 allows for very flexible control over data and assemble points. Output file formats are completely independent of the final memory maps.
- Multiple file support - libraries may be kept as seperate files and included seperately, facilitating code reuse.
- Temporary label support - source may contain "anonymous labels" that help decrease namespace pollution. P65-Ophis also supports named temporary labels that only exist within a well-defined scope.
- Assemble-time expressions - P65-Ophis supports High-byte/low-byte computations along with bitmasking and traditional arithmetic operations in code and data statements. Access to the current PC is also supported. P65-Perls expressions are more limited but are generally sufficient.
- Symbol table management - Allows for creating labels and data constants outside of the code, and for allocating RAM symbolically. This includes full support for segments.
- Optimal instruction selection - Compresses as many instructions as possible into zero page format. If this compression permits other instructions to become zero page instructions, it will compress those as well.