Spectrum ROM: Routine at 0053

0053: THE 'ERROR-2' ROUTINE

Used by the routine at ERROR_1. The return address to the interpreter points to the 'DEFB' that signifies which error has occurred. This 'DEFB' is fetched and transferred to ERR-NR. The machine stack is cleared before jumping forward to clear the calculator stack.
ERROR_2	0053	POP HL	The address on the stack points to the error code.
	0054	LD L,(HL)	The address on the stack points to the error code.
This entry point is used by the routine at TEST_ROOM.
ERROR_3	0055	LD (IY+$00),L	It is transferred to ERR-NR.
	0058	LD SP,($5C3D)	The machine stack is cleared by setting the stack pointer to ERR-SP before exiting via SET_STK.
	005C	JP SET_STK