ophis (cross assembler for 6502)

Ophis is a cross-assembler for the 65xx series of chips. It supports
the stock 6502 opcodes, the 65c02 extensions, experimental support
for the 4502/4510 used in the Commodore 65 prototypes, and syntax
for the "undocumented opcodes" in the 6510 chip used on the Commodore
64 (syntax for these opcodes matches those given in the VICE team's
documentation).

Ophis is written in pure Python and should be highly portable.

The package includes ophis itself, the platform
headers in /usr/share/ophis, and the PDF manual in
/usr/doc/ophis-$VERSION/ophismanual.pdf.
If you prefer the manual in HTML form, it's here:

https://michaelcmartin.github.io/Ophis/book/book1.html