The Hobbit (v1.0): Routine at A178

Only the rope can be tied: TIE THE ROPE TO X is turned round into TIE X TO THE ROPE (A1DE, 9E93). The thing tied must not be something that pours, must be empty ('the rope is already tied'), and must not be a living character (a dead one is fine). It then becomes held by the rope.

If the actor could pick the thing up, the rope stays in the actor's hands with the thing hanging from it; otherwise the rope is left lying, tied to it. Taking or dropping the rope takes or drops whatever is tied to it (8CC8, 8C45).

Only the rope can be tied: TIE THE ROPE TO X is turned round into TIE X TO THE ROPE (A1DE, 9E93). The thing tied must not be something that pours, must be empty ('the rope is already tied'), and must not be a living character (a dead one is fine). It then becomes held by the rope. If the actor could pick the thing up, the rope stays in the actor's hands with the thing hanging from it; otherwise the rope is left lying, tied to it. Taking or dropping the rope takes or drops whatever is tied to it (8CC8, 8C45).
A178	LD A,($B5D9)	Is the TARGET actually the rope (object 18)?
A17B	CP $12	Is the TARGET actually the rope (object 18)?
A17D	JR Z,$A1DE	Yes: "TIE THE ROPE TO X" - turn it round into "TIE X TO THE ROPE" (below)
A17F	LD A,($B5DA)	No: is the INSTRUMENT the rope instead?
A182	CP $12	No: is the INSTRUMENT the rope instead?
A184	JP NZ,$9EBF	Neither: fail with the usual message - only the rope can be tied
A187	LD IX,($B5F8)	IX = the target's own record (the thing being tied)
A18B	BIT 1,(IX+$07)	Does it pour (is it a liquid)?
A18F	JP NZ,$9EBF	Yes: cannot tie up a liquid
A192	CALL $9CEC	Does it already hold anything visible?
A195	CP $00	Does it already hold anything visible?
A197	LD HL,$AF6F	"the X is already tied."
A19A	JP NZ,$72D4	Already holding something (i.e. already tied to something): say so and stop
A19D	BIT 3,(IX+$07)	Is it dead (a corpse)?
A1A1	JR NZ,$A1AA	Yes: a dead character may still be tied up
A1A3	BIT 6,(IX+$07)	No: is it a LIVING character?
A1A7	JP NZ,$9EBF	Yes: cannot tie up someone alive
A1AA	CALL $9C99	Dry run? Then stop here: it would work
A1AD	LD IY,($B5FA)	IY = the rope's own record
A1B1	CALL $9BCD	Is the actor already holding the thing being tied?
A1B4	LD A,($B5DA)	It becomes held by the rope, either way...
A1B7	LD (IX+$01),A	It becomes held by the rope, either way...
A1BA	JR C,$A1D2	If the actor already held it, skip straight to deciding who holds the rope itself
A1BC	SUB A	Otherwise: try to pick it up first (as an ordinary TAKE), but only as a trial for now
A1BD	LD ($B5EB),A
A1C0	CALL $8CC8
A1C3	LD A,($B5EC)	Did the actor manage to pick it up?
A1C6	CP $00	Did the actor manage to pick it up?
A1C8	LD A,$01	Either way, this really is happening now
A1CA	LD ($B5EB),A
A1CD	LD ($B5EC),A
A1D0	JR Z,$A1D9	Could not pick it up: leave the rope where it is, below
A1D2	LD A,($B5DB)	Could pick it up: the rope stays in the actor's own hands
A1D5	LD (IY+$01),A
A1D8	RET
A1D9	LD (IY+$01),$FF	Left lying: the rope is held by nobody, tied to whatever is too heavy to lift
A1DD	RET
A1DE	LD HL,$A178	"TIE THE ROPE TO X": run this same handler again...
A1E1	JP $9E93	...with target and instrument swapped, so it becomes "TIE X TO THE ROPE"