See $LK,"::/Compiler/OpCodes.DD"$ for opcodes. They're not standard. Some invalid insts are not flagged and some valid insts are not implemented. 16-bit asm support is limited.
Define BYTE, WORD, DWORD or QWORD. Can be used with $FG,2$DUP()$FG$ and ASCII strings. For your convenience, the ASCII strings do not have terminating zeros. Define cmds must end with a semicolon.
See $LK,"Assembly Language",A="FF:::/Doc/GuideLines.DD,Assembly Language"$, $LK,"::/Demo/Asm/AsmAndC1.CC"$, $LK,"::/Demo/Asm/AsmAndC2.CC"$ and $LK,"::/Demo/Asm/AsmAndC3.CC"$.