Use that PC for something good!
This section contains information relating to specific assemblers of cross-dev systems.
Also check the syntax highlighting section below which contains syntax highlighting files for various assemblers for various text editors.
Also have a look at the source code conversion page if you want to know how to convert your sources from turbo assembler (petscii) to ascii, and how to (re)indent code that is messy. Also note that there is a list of commonly used assemblers on the Most used tools page.
ca65 is an assembler which is part of the cc65 suite of tools.
DreamAss is perhaps the most turbo-assembler-alike assembler, expanded with macros.
This section is for 6502/6510 assembler syntax highlighting files.