(* REGISTER USAGE & DEDICATED REGISTERS: *) (* D-REGISTER POOL FOR EXPRESSION EVALUATION.*) D0 = 0; (* freely used, never reserved.*) D1 = 1; D2 = 2; D3 = 3; D4 = 4; D5 = 5; (* reserved when used.*) D6 = 6; D7 = 7; (* A-REGISTER POOL FOR ADDRESS CALCULATIONS.*) A0 = 0; (* freely used, never reserved.*) A1 = 1; A2 = 2; A3 = 3; A4 = 4; (* reserved when used.*) (* DEDICATED A-REGISTERS: *) A5 = 5; PD = 5; (* pointer to active process descriptor.*) A6 = 6; MP = 6; (* stack marker for local vars./params. *) A7 = 7; SP = 7; (* active stack pointer. *)