; 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

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

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

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

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

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

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