Allows you to add an instruction to the Z80 instruction set at runtime.
.addinstr instruction args opcode size rule class [shift [or]]
This directive only affects the Z80 assembler.
As the bundled Z80 assembler only supports a small subset of TASM's instruction types (NOP, R1, ZIX, ZBIT) this directive is of limited usefulness.
See TASMTABS.HTM in TASM's zip file for more information.