BSO CR6502/11 (VAX) In mid-1984, Commodore switched to “CR6502/11” by the company Boston Systems Office (BSO), a cross-assembler running on VAX/VMS systems that was highly compatible to the MOS assemblers, but more advanced. Read more: Commodore’s Assemblers: Part 3: BSO [coming soon] HCD65 (C128) In 1986, Commodore wrote a new assembler named “HCD65” for the C128 that aimed at full compatibility with the BSO assembler. They sold it as part of the Commodore 128 Developer’s Package in 1987. In 1989, as Commodore worked on the ill-fated C65, they added support for the extended 65CE02/4510 instruction set. Read more: Commodore’s Assemblers: Part 4: HCD65 [coming soon]