Device	Error			Action

CDR	RN, RA invalid char	set RDCHK; if IOSTOP set, stop simulator with INVCHR
	unattached		stop simulator with UNATT (CHANGED - used to set RDCHK too)
	end of file		stop simulator witn NOCD (CHANGED - used to set RDCHK too)
	file read error		set RDCHK; stop simulator with IOERR
	input line too long	set RDCHK; stop simulator with IOERR

CDP	WN,DN invalid digit	set WRCHK; if IOSTOP set, stop simulator with INVCHR
	WA invalid char		set WRCHK; if IOSTOP set, stop simulator with INVCHR
	unattached		stop simulator with UNATT (CHANGED - used to set WRCHK too)
	file write error	set WRCHK; stop simulator with IOERR

LPT	bad K control field	set PRCHK; if IOSTOP set, stop simulator with INVFNC
	WN,DN invalid digit	set PRCHK and WRCHK; if IOSTOP set, stop simulator with INVFNC
	WA invalid char		set PRCHK and WRCHK; if IOSTOP set, stop simulator with INVFNC
	unattached		stop simulator with UNATT (CHANGED - used to set WRCHK too)
	file write error	set PRCHK and WRCHK; stop simulator with IOERR

PTR	RN, RA invalid char	set RDCHK but complete operation; if IOSTOP set at end, stop simulator with INVCHR
	RN, RA parity error	set RDCHK but complete operation; if IOSTOP set at end, stop simulator with INVCHR
	WN, DN invalid digit	set WRCHK; if IOSTOP set, stop simulator with INVCHR
	WA invalid char		set WRCHK; if IOSTOP set, stop simulator with INVCHR
	unattached		stop simulator with UNATT (CHANGED - used to set WRCHK too)
	file write error	set WRCHK; stop simulator with IOERR

TTY	RN, RA invalid char	ignored, echoed as beep/bell
	WN, DN invalid digit	ignored, printed as :
	WA invalid char		set WRCHK; if IOSTOP set, stop simulator with INVCHR