The Sidney Affair: Routine at FC86

FC86: Print String

Prints the BASIC string "s$" at the current print position in a 64-column font. It finds the string with the ROM routine LOOK-VARS, using the name at PrintString_VariableName, and stops with an error if it is missing. Codes below 20 go straight to RST 10; codes from 90 upwards are skipped. Called by BASIC as "prn" (FC86).
PrintString	FC86	DI	Disable interrupts.
	FC87	LD ($FF76),SP
	FC8B	LD SP,$FFBE
	FC8E	XOR A
	FC8F	LD ($FD02),A
	FC92	LD A,$02
	FC94	CALL $1601
	FC97	LD HL,$FC83
	FC9A	CALL MatchString_LookUpVariable
	FC9D	JR Z,PrintString_3
PrintString_0	FC9F	LD A,(HL)
	FCA0	INC HL
	FCA1	CP $90
	FCA3	JR NC,PrintString_2
	FCA5	CP $20
	FCA7	JR NC,PrintString_1
	FCA9	RST $10
	FCAA	JR PrintString_2
PrintString_1	FCAC	CALL PrintString_Character
PrintString_2	FCAF	DEC BC
	FCB0	LD A,B
	FCB1	OR C
	FCB2	JR NZ,PrintString_0
PrintString_3	FCB4	LD A,($FD02)
	FCB7	OR A
	FCB8	JR Z,PrintString_4
	FCBA	LD A,$20
	FCBC	CALL PrintString_Character
PrintString_4	FCBF	LD SP,($FF76)
	FCC3	RET