;======================================================================
; UART and Baud Rate initialization code
;=======================================
;
;	Control program for Morrow Terminal
;	Copyright 1984
;	Morrow Designs, Inc.
;	San Leandro, Ca.
;
;	Written by David Block and Jim Kearney (September 1983)
;
;----------------------------------------------------------------------
; Uart Initialization
;--------------------
;
INIUART	JSR	SETBAUD		; determine baud rate selection bits
	JSR	SETUART		; setup UART for proper BAUD rate, etc
	JSR	INIT8		; set status of bit 8 parity, or mark, or space
	RTS

;----------------------------------------------------------------------
; Determine the Baud Rate Settings
;---------------------------------
;
SETBAUD	LDA	BDREG		; get current contents of baud register
	AND	#$F9		; Clear BD0 and BD1
	STA	BDREG
	LDA	DIP1		; get dipsw value
	AND	#$03		; get baud rate selection bits
	ASL	A		; align with BDREG
	ORA	BDREG		; set/clr baud bits
	STA	BDREG		; Save it
	STA	BAUD		; and set baud bits
	RTS
	PAGE

;----------------------------------------------------------------------
; Set the Uart Baud Rate
;-----------------------
;
SETUART	LDX	#$80		; after setting baud rate, wait to settle
UARTDLY	DEX
	BNE	UARTDLY

	LDA	#$80		; reset USART
	STA	S1STAT
	TAX
	TAX			; WAIT
	STA	S1STAT
	LDA	#$40
	STA	S1STAT		; Put USART in command mode
	LDA	DIP1		; get dip switch settings
	AND	#%00001100	; get the parity select bits
	ASL	A
	ASL	A		; align them for USART Mode byte
	STA	TEMP		; put it aside
	LDA	DIP1		; get dip switch 
	AND	#%00000010	; determine if it needs /16 or /64
	LSR	A		; move the determining bit over
	ORA	TEMP		; get parity select bits back
	ORA	#%01001110	; OR in USART MODE boiler plate (8-data, 1-stop)
	STA	S1STAT		; set USART Mode
	LDA	#%00110111	; get enable byte for USART
	STA	S1STAT		; Enable USART
	STA	UARTCMD		; save it in command instr. register
	LDA	S1DATA		; Flush one character
	RTS

;----------------------------------------------------------------------
; Set Transmission/Reception Format
;----------------------------------
;
INIT8	LDA	DIP1		; get dip setings
	LSR	A		; get parity on/off status
	LSR	A
	TAX
	AND	#%00000001
	STA	PARSTAT		; save it in parity status
	TXA
	LSR	A
	AND	#%00000001	; get whether mark or space/ odd/even
	STA	BIT8
	RTS
	PAGE

	END