Preparation		TALK, TKSA
Send	.A	ignored
	.X	ignored
	.Y	ignored
Stack usage		13
Returns	.A	Byte from serial bus
	.X	undefined
	.Y	preserved
Errors		See READST

Preparation		(OPEN)
Send	.A	ignored
	.X	File number
	.Y	ignored
Stack usage		None
Returns	.A	undefined
	.X	undefined
	.Y	preserved
Errors		None

Preparation		(OPEN)
Send	.A	ignored
	.X	File number
	.Y	ignored
Stack usage		4+
Returns	.A	undefined
	.X	undefined
	.Y	preserved
Errors		0,3,5,7 (See READST)

Preparation		(OPEN, CHKIN)
Send	.A	ignored
	.X	ignored
	.Y	ignored
Stack usage		7+
Returns	.A	Retrieved byte
	.X	undefined
	.Y	preserved
Errors		0 (See READST)

Preparation		(CHKOUT,OPEN)
Send	.A	Byte to send
	.X	ignored
	.Y	ignored
Stack usage		8+
Returns	.A	undefined
	.X	preserved
	.Y	preserved
Errors		0 (See READST)

Preparation		None
Send	.A	ignored
	.X	ignored
	.Y	ignored
Stack usage		4
Returns	.A	undefined
	.X	undefined
	.Y	undefined
Errors		None

Preparation		LISTEN, [SECOND]
Send	.A	Byte to send
	.X	ignored
	.Y	ignored
Stack usage		5
Returns	.A	preserved
	.X	preserved
	.Y	preserved
Errors		See READST

Preparation		None
Send	.A	ignored
	.X	ignored
	.Y	ignored
Stack usage		11
Returns	.A	undefined
	.X	undefined
	.Y	preserved
Errors		None

Preparation		None
Send	.A	File number
	.X	ignored
	.Y	ignored
Stack usage		2+
Returns	.A	undefined
	.X	undefined
	.Y	undefined
Errors		0,240 (See READST)

Preparation		None
Send	.A	ignored
	.X	ignored
	.Y	ignored
Stack usage		9
Returns	.A	undefined
	.X	undefined
	.Y	preserved
Errors		None

Preparation		CHKIN, OPEN
Send	.A	ignored
	.X	ignored
	.Y	ignored
Stack usage		7+
Returns	.A	undefined
	.X	undefined
	.Y	undefined
Errors		See READST

Preparation		None
Send	.A	ignored
	.X	ignored
	.Y	ignored
Stack usage		2
Returns	.A	preserved
	.X	Low byte of I/O hardware location
	.Y	High byte of I/O hardware location
Errors		None

Preparation		None
Send	.A	ignored
	.X	ignored
	.Y	ignored
Stack usage		None
Returns	.A	undefined
	.X	undefined
	.Y	undefined
Errors		None

Preparation		None
Send	.A	Device number
	.X	ignored
	.Y	ignored
Stack usage		None
Returns	.A	undefined
	.X	preserved
	.Y	preserved
Errors		See READST

Preparation		SETLFS, SETNAM
Send	.A	0 for Load, 1 for Verify
	.X	[Low byte of load address]
	.Y	[High byte of load address]
Stack usage		None
Returns	.A	undefined
	.X	Low byte of ending address
	.Y	High byte of ending address
Errors		0,4,5,8,9, READST

Preparation		None
Send	.A	ignored
	.X	[Low byte of new RAM bottom]
	.Y	[High byte of new RAM bottom]
Stack usage		None
Returns	.A	preserved
	.X	[Low byte of current RAM bottom]
	.Y	[High byte of current RAM bottom]
Errors		None

Preparation		None
Send	.A	ignored
	.X	[Low byte of new RAM top]
	.Y	[High byte of new RAM top]
Stack usage		2
Returns	.A	preserved
	.X	[Low byte of current RAM top]
	.Y	[High byte of current RAM top]
Errors		None

Preparation		SETLFS, SETNAM
Send	.A	ignored
	.X	ignored
	.Y	ignored
Stack usage		None
Returns	.A	undefined
	.X	undefined
	.Y	undefined
Errors		1,2,4,5,6,240, READST

Preparation		None
Send	.A	ignored
	.X	[New cursor row]
	.Y	[New cursor column]
Stack usage		2
Returns	.A	undefined
	.X	[Current cursor row]
	.Y	[Current cursor column]
Errors		None

Preparation		None
Send	.A	ignored
	.X	ignored
	.Y	ignored
Stack usage		2
Returns	.A	undefined
	.X	undefined
	.Y	undefined
Errors		None

Preparation		None
Send	.A	ignored
	.X	ignored
	.Y	ignored
Stack usage		2
Returns	.A	High byte of system time
	.X	Middle byte of system time
	.Y	Low byte of system time
Errors		None

Preparation		None
Send	.A	ignored
	.X	ignored
	.Y	ignored
Stack usage		2
Returns	.A	Status code
	.X	preserved
	.Y	preserved
Errors		None

Preparation		None
Send	.A	ignored
	.X	ignored
	.Y	ignored
Stack usage		2
Returns	.A	undefined
	.X	undefined
	.Y	undefined
Errors		None

Preparation		SETLFS, SETNAM
Send	.A	Zero-page location of the start address pointer
	.X	Low byte of ending address
	.Y	High byte of ending address
Stack usage		None
Returns	.A	undefined
	.X	undefined
	.Y	undefined
Errors		5,8,9, READST

Preparation		IOINIT
Send	.A	ignored
	.X	ignored
	.Y	ignored
Stack usage		5
Returns	.A	undefined
	.X	undefined
	.Y	undefined
Errors		None

Preparation		None
Send	.A	ignored
	.X	ignored
	.Y	ignored
Stack usage		2
Returns	.A	preserved
	.X	Number of screen columns
	.Y	Number of screen rows
Errors		None

Preparation		LISTEN
Send	.A	Secondary address
	.X	ignored
	.Y	ignored
Stack usage		8
Returns	.A	undefined
	.X	preserved
	.Y	preserved
Errors		See READST

Preparation		2
Send	.A	A, X, Y
	.X	None
	.Y	None
Stack usage
Returns	.A	SETMSG
	.X	Control system message output
	.Y	$FF90
Errors		None

Preparation		Set file name
Send	.A	A
	.X
	.Y	SETNAM
Stack usage		65469
Returns	.A	A, X, Y
	.X	None
	.Y	None
Errors		$FFBD

Preparation		None
Send	.A	$FFDB
	.X	65499
	.Y	A, X, Y
Stack usage		2
Returns	.A	None
	.X
	.Y	SETTMO
Errors		None

Preparation
Send	.A	None
	.X	2
	.Y	None
Stack usage		Check if key is pressed
Returns	.A	$FFE1
	.X	65505
	.Y	A
Errors		STOP

Preparation		65460
Send	.A	TALK
	.X	Command a device on the serial bus to TALK
	.Y	$FFB4
Stack usage		None
Returns	.A	See READST
	.X	8
	.Y	A
Errors		A

Preparation		8
Send	.A	A
	.X	TALK
	.Y	See READST
Stack usage
Returns	.A	UDTIM
	.X	Update the system clock
	.Y	$FFEA
Errors		A

Preparation		Send an UNLISTEN command
Send	.A	A, X
	.X
	.Y	UNLSN
Stack usage		65454
Returns	.A	None
	.X	None
	.Y	See READST
Errors		$FFAE

Preparation		None
Send	.A	$FF8D
	.X	65421
	.Y	X, Y
Stack usage		2
Returns	.A	A, X, Y
	.X	None
	.Y	See READST
Errors		None