SUBTTL VMDDT -- VIRTUAL (INVISIBLE) DDT FTDEC10==-1 ;FOR A TOPS-10 SYSTEM FTDEC20==0 ;NOT FOR TOPS-20 FTEXEC==0 ;NO EXEC MODE DDT (ALSO RUNS IN USER MODE) FTFILE==0 ;NO FILDDT FTYANK==-1 ;YANK COMMAND ($Y) FTVMX==-1 ;TOPS-10 DDT.VMX FTMON==0 ;NO MDDT (TOPS-20 ONLY) FTOPX==-1 ;DO EXTENSIVE OPCODE DECODING