# Command Codes
WRITE_TEXT            = "A"  # Write TEXT file (p18)
READ_TEXT             = "B"  # Read TEXT file (p19)
WRITE_SPECIAL         = "E"  # Write SPECIAL FUNCTION commands (p21)
READ_SPECIAL          = "F"  # Read SPECIAL FUNCTION commands (p29)
WRITE_STRING          = "G"  # Write STRING (p37)
READ_STRING           = "H"  # Read STRING (p38)
WRITE_SMALL_DOTS      = "I"  # Write SMALL DOTS PICTURE file (p39)
READ_SMALL_DOTS       = "J"  # Read SMALL DOTS PICTURE file (p41)
WRITE_RGB_DOTS        = "K"  # Write RGB DOTS PICTURE file (p44)
READ_RGB_DOTS         = "L"  # Read RGB DOTS PICTURE file (p46)
WRITE_LARGE_DOTS      = "M"  # Write LARGE DOTS PICTURE file (p42)
READ_LARGE_DOTS       = "N"  # Read LARGE DOTS PICTURE file (p43)
WRITE_ALPHAVISION     = "O"  # Write ALPHAVISION BULLETIN (p48)
SET_TIMEOUT           = "T"  # Set Timeout Message (p118) (Alpha 2.0/3.0)

UNLOCKED              = "U"
LOCKED                = "L"

# Constants used in transmission packets
NUL                   = "\x00"  # NULL
SOH                   = "\x01"  # Start of Header
STX                   = "\x02"  # Start of TeXt (precedes a command code)
ETX                   = "\x03"  # End of TeXt
EOT                   = "\x04"  # End Of Transmission
#ENQ                   = "\x05"  # Enquiry
#ACK                   = "\x06"  # Acknowledge
BEL                   = "\x07"  # Bell
BS                    = "\x08"  # Backspace
HT                    = "\x09"  # Horizontal tab
LF                    = "\x0A"  # Line Feed
NL                    = "\x0A"  # New Line
VT                    = "\x0B"  # Vertical Tab
#FF                    = "\x0C"  # Form Feed
NP                    = "\x0C"  # New Page
CR                    = "\x0D"  # Carriage Return
CAN                   = "\x18"  # Cancel
SUB                   = "\x1A"  # Substitute (select charset)
ESC                   = "\x1B"  # Escape character

NEWLINE               = NL
NEWPAGE               = NP