; ascii.h -- names for ASCII control characters
; language:   SMAL32 assembly language, intended as an include file
; author:     Douglas W. Jones
; date:       Dec 1, 2019
; revised:    Jan 4, 2024 -- comments added documenting the common ones
; revised:    May 30, 2024 -- use =: for immutable names, use _ to mean private

_CTRL_	=	-'@'		; control key (symbol used only locally)

NUL	=:	_CTRL_ + '@'	; C-style end of string
SOH	=:	_CTRL_ + 'A'
STX	=:	_CTRL_ + 'B'
ETX	=:	_CTRL_ + 'C'
EOT	=:	_CTRL_ + 'D'
ENQ	=:	_CTRL_ + 'E'
ACK	=:	_CTRL_ + 'F'
BEL	=:	_CTRL_ + 'G'	; audible alert (ding, beep)

BS	=:	_CTRL_ + 'H'	; backspace
HT	=:	_CTRL_ + 'I'	; tab
LF	=:	_CTRL_ + 'J'	; line feed (down one line)
VT	=:	_CTRL_ + 'K'
FF	=:	_CTRL_ + 'L'	; form feed or screen erase
CR	=:	_CTRL_ + 'M'	; carriage return, enter or newline
SO	=:	_CTRL_ + 'N'
SI	=:	_CTRL_ + 'O'

DLE	=:	_CTRL_ + 'P'
DC1	=:	_CTRL_ + 'Q'
DC2	=:	_CTRL_ + 'R'
DC3	=:	_CTRL_ + 'S'
DC4	=:	_CTRL_ + 'T'
NAK	=:	_CTRL_ + 'U'
SYN	=:	_CTRL_ + 'V'
ETB	=:	_CTRL_ + 'W'

CAN	=:	_CTRL_ + 'X'
EM	=:	_CTRL_ + 'Y'
SUB	=:	_CTRL_ + 'Z'
ESC	=:	_CTRL_ + '['	; escape
FS	=:	_CTRL_ + '\'
GS	=:	_CTRL_ + ']'
RS	=:	_CTRL_ + '^'
US	=:	_CTRL_ + '_'

SP	=:	' '		; space
DEL	=:	#7F		; delete or rub out, overwrite bad data, ignore