;======================================================================
; Interrupt handlers (12_Nov_84)
;===============================
;
;	Control program for Morrow Terminal
;	Copyright 1984
;	Morrow Designs, Inc.
;	San Leandro, Ca.
;
;	Written by  David Block and Jim Kearney	(September 1983)
;
;
;----------------------------------------------------------------------
; Irq occurs when the keyboard wants to send a char to the processor
;-------------------------------------------------------------------
;
FTCHKEY:PLA			; fix so RTI returns properly
	TAX
	INX
	TXA
	PHA
	PHP

IRQVEC:	PHA
	TYA			; else
	PHA			; 	save registers
	TXA
	PHA
	JSR	GETKEY		; 	get key from keyboard
	LDY	LOCKMD		; see if keyboard locked
	BMI	IRQRET		; if (keyboard locked) then return

	JSR	KEYINS		; else,	insert character key buffer
IRQRET:	PLA
	TAX			; restore registers
	PLA
	TAY
	PLA			; and return
	RTI
	PAGE

;----------------------------------------------------------------------
; Ok, we've got a character interrupt from the USART.
;----------------------------------------------------
;
NMIRET:	LDA	S1DATA		; clear NMI, and throw away the character
	PLA
	RTI

NMIVEC:	SEI			; disable interrupts
	PHA
	LDA	NMIOK		; see if NMI is enabled
	CMP	#$A5		; must be A5 to handle interrupts
	BNE	NMIRET

	TYA			; save other registers
	PHA
	TXA
	PHA
	LDA	S1DATA		; GET A CHARACTER FROM USART
	AND	#%01111111	; ignore the eighth bit
	CMP	#$0		; don't put nulls in buffer
	BEQ	NOINS

	JSR	ININS		; put in incoming character buffer if room exists
NOINS:	PLA
	TAX
	PLA
	TAY
	PLA
	RTI
	PAGE

	END