Path: utzoo!utgpu!attcan!uunet!peregrine!elroy!ames!mailrus!ncar!gatech!mcnc!rti!sunpix!matthew
From: matthew@sunpix.UUCP ( Sun NCAA)
Newsgroups: comp.sys.apple
Subject: Re: Configuring Serial Ports ...
Keywords: help
Message-ID: <257@greens.UUCP>
Date: 2 Nov 88 21:59:51 GMT
References: <2340@cs.Buffalo.EDU>
Organization: Sun Microsystems, Research Triangle Park, NC
Lines: 90

In article <2340@cs.Buffalo.EDU>, ugfelong@cs.Buffalo.EDU (Edward Felong) writes:
> 
> What exactly happens when the serial ports are configured ?
> Some of my software doesn't recognize a 4800 baud printer
> in slot 1 unless I turn the computer on with system utilities first.
> Can I just BSAVE a section of memory and BLOAD it with startup
> program ?
> 
The serial port configurations are stored in auxilary memory as follows:

$0478 thru $047B - Serial Port #1
=================================
$0478	ACIA control register

$0479	ACIA command register

$047A	Flags
	bit 7:	echo output on display ( 0 = no echo )
	bit 6:	generate LF after CR   ( 0 = no LF )
	bit 5:	always 0
	bit 4:	always 0
	bit 3:	always 0
	bit 2:	always 0
	bit 1:	always 0
	bit 0:	1 = communications port; 0 = printer port

$047B	max line length 
	bit 7 - 1:	line length ( 0 = do not insert CR )

$047C thru $047F - Serial Port #1
=================================
$047C	ACIA control register

$047D	ACIA command register

$047E	Flags
	bit 7:	echo output on display ( 0 = no echo )
	bit 6:	generate LF after CR   ( 0 = no LF )
	bit 5:	always 0
	bit 4:	always 0
	bit 3:	always 0
	bit 2:	always 0
	bit 1:	always 0
	bit 0:	1 = communications port; 0 = printer port

$047F	max line length 
	bit 7 - 1:	line length ( 0 = do not insert CR )


to capture these values using machine language do the following:

	LDA	#$04
	STA	$3D	#SET SOURCE START HIGH
	STA	$3F	#SET SOURCE END HIGH
	LDA	#$78
	STA	$3C	#SET SOURCE START LOW
	LDA	#$7F
	STA 	$3D	#SET SOURCE END LOW
	LDA	#$03
	STA	$43	#SET DESTINATION HIGH
	LDA	#$00
	STA	$42	#SET DESTINATION LOW
	SEC		#FLAG A MOVE FROM AUX MEMORY
	JSR	$C311	#DO THE ACTUAL MOVE
	RTS		#MAIN MEMORY $0300-$0307 NOW HAVE VALUES

and this to set all of them:

	LDA	#$03
	STA	$3D	#SET SOURCE START HIGH
	STA	$3F	#SET SOURCE END HIGH
	LDA	#$00
	STA	$3C	#SET SOURCE START LOW
	LDA	#$07
	STA 	$3D	#SET SOURCE END LOW
	LDA	#$04
	STA	$43	#SET DESTINATION HIGH
	LDA	#$78
	STA	$42	#SET DESTINATION LOW
	CLC		#FLAG A MOVE TO AUX MEMORY
	JSR	$C311	#DO THE ACTUAL MOVE
	RTS		#AUX MEMORY $0478-$047F NOW HAS 
			#MAIN MEMORY $0300-$0307  VALUES



-- 
Matthew Lee Stier     (919) 469-8300|
Sun Microsystems ---  RTP, NC  27560|          "Wisconsin   Escapee"
uucp: {sun, rti}!sunpix!matthew     |