AssemblerJS

(v0.6.12) Load a 6502 .S source file. Source is shown left, assembly listing in the middle, JSON at right, and byte code below. Listing columns are editable in the listing header. UI height-sync build: the listing pane determines the source/JSON pane height after ASSEMBLE.
Tip: drag a .S file anywhere on this page
Ready.
Source
Listing compile()
JSON output not assembled
Byte code 0 bytes