$GETDVI returns terminal characteristics when you specify
the item codes DVI$_DEVCHAR, DVI$_DEVDEPEND, and DVI$_DEVDEPEND2.
Terminal Device-Independent Characteristics,
Terminal Characteristics, and
Extended Terminal Characteristics list
these characteristics. Terminal characteristics are normally set
during system generation to any one of, or a combination of, the values
listed in
Terminal Characteristics. DVI$_DEVDEPEND
returns a longword field in which the three low-order bytes contain
the device-dependent characteristics and the high-order byte contains
the page length. Page length can have a value in the range of 0
through 255. The $DEVDEF macro defines the device-independent characteristics,
the $TTDEF macro defines the device-dependent characteristics, and
the $TT2DEF macro defines the extended device-dependent characteristics.
DVI$_DEVCLASS and DVI$_DEVTYPE return the device class and
device type names, which are defined by the $DCDEF and $TTDEF macros,
respectively. The device class for terminals is DC$_TERM. The terminal model
determines the device type. For example, the device type for the
VT240 is TT$_VT200_SERIES. DVI$_DEVBUFSIZ returns the page width,
which can be a value in the range of 1 through 511. The driver does
not accept a value of 0.
Table 5 Terminal Characteristics
Value1 |
Meaning |
TT$M_CRFILL
|
Terminal requires fill after
the Return key is pressed (the fill type can be specified by the
set mode function P4 argument).
|
TT$M_EIGHTBIT
|
Terminal uses the 8-bit
ASCII character set (see
Tables).
Terminals without this characteristic use the 7-bit ASCII code.
In this case, the eighth bit is masked out on received characters
and is ignored on output characters. The eighth bit is meaningful
only if TT$M_EIGHTBIT is set.
|
TT$M_ESCAPE
|
Terminal generates escape
sequences (see
Escape and Control Sequences). Escape sequences are validated for syntax.
|
TT$M_HALFDUP
|
Terminal is in half-duplex
mode (see
Duplex Modes). All read and
write requests are executed sequentially.
|
TT$M_HOSTSYNC
|
The host system is synchronized
to the terminal. Ctrl/Q and Ctrl/S are used to control data flow
and thus keep the type-ahead buffer from filling. TT$M_HOSTSYNC
should always be set on LAT terminals.
|
TT$M_LFFILL
|
Terminal requires fill after
the line-feed character is processed. (The fill can be specified
by the set mode P4 argument.)
|
TT$M_LOWER
|
Terminal has the lowercase
character set. Unless the terminal
is in the PASTHRU mode or IO$M_NOFORMAT is specified, all input
and echoed lowercase characters (hexadecimal 61 to 7A) are converted
to uppercase if TT$M_LOWER is not set. (The character ALTMODE (decimal
125 and 126, or hexadecimal 7D and 7E) converts to ESCAPE on terminals
that do not have the lowercase characteristic TT$M_LOWER set.)
|
TT$M_MBXDSABL
|
Mailboxes associated with
the terminal do not receive notification
of unsolicited input or hangup (see
Dialup Support). This bit can be set by tshe IO$M_DSABLMBX
function modifier for read requests and cleared by the IO$M_ENABLMBX
function modifier for write requests.
|
TT$M_MECHFORM
|
Terminal has mechanical
form feed. The terminal driver passes form feeds directly
to the terminal instead of expanding to line feeds.
|
TT$M_MECHTAB
|
Terminal has mechanical
tabs and is capable of tab expansion. To accomplish correct line wrapping, the terminal
driver assumes there are eight spaces between tab stops.
|
TT$M_MODEM
|
Terminal line is connected
to a modem. If TT$M_MODEM is set,
the terminal driver automatically handles modem control. If TT$M_MODEM
is not set, all modem signals are ignored. If TT$M_MODEM is set
and then cleared, a hangup is declared on the terminal line if that
line is in the remote state (TT$M_REMOTE is set). If DTR and RTS
are set with IO$_SETMODE!IO$M_SET_MODEM!IO$M_MAINT on a nonmodem port,
DTR and RTS goes off and then back on when the port is set for modem.
TT$M_MODEM
is not supported for LAT devices.
|
TT$M_NOBRDCST
|
Terminal does not receive
any broadcast messages.
|
TT$M_NOECHO
|
Input characters are not
echoed on this terminal line (see
Type-Ahead Feature).
|
TT$M_NOTYPEAHD
|
Data must be solicited by
a read operation. Data is lost if
received in the absence of an outstanding read request (if it is
unsolicited data). Disables type-ahead feature (see
Type-Ahead Feature). If this characteristic is
set, login attempts on this line are disabled. See
Modem Signal Control for information
on modem signal control.
|
TT$M_READSYNC
|
Read synchronization is
enabled. The host explicitly solicits all read operations by entering
a Ctrl/Q and terminates the operation by entering a Ctrl/S. TT$M_READSYNC
is not applicable to LAT terminals.
|
TT$M_REMOTE
|
Dialup characteristic is
enabled. The terminal returns to local
mode when a hangup occurs on the terminal line (see Section
Dialup Support). This characteristic
cannot be changed; it is only informational.
|
TT$M_SCOPE
|
Terminal is a video screen
display (CRT terminal), for example, the VT100 or VT240 terminals.
|
TT$M_TTSYNC
|
The terminal is synchronized
to the host system. Output to the terminal is controlled by terminal-generated
Ctrl/Q or Ctrl/S. TT$M_TTSYNC is not applicable to LAT terminals
unless TT$M_PASTHRU is set and TT$M_TTSYNC is disabled, in which
case the LAT session is placed in PASSALL mode.
|
TT$M_WRAP
|
A carriage-return/line-feed combination
should be inserted if the cursor moves beyond the right margin.
If TT$M_WRAP is not set, no carriage-return/line-feed combination
is sent. The operating system does not support hardware-provided
wrapping functions.
|
Table 6 Extended Terminal Characteristics
Value2 |
Meaning |
TT2$M_ALTYPEAHD
|
Alternate type-ahead buffer
size is enabled. Use the alternate type-ahead
buffer size specified during system generation (see
Type-Ahead Feature). If a type-ahead buffer already exists
for a terminal line, there is no effect when this characteristic
is set for that line. TT2$M_ALTYPEAHD should be set prior to using the
terminal, such as in the startup command procedure. You can only set
TT2$M_ALTYPEAHD; this characteristic cannot be cleared until the
system is rebooted.
|
TT2$M_ANSICRT
|
ANSI CRT terminal is enabled. This characteristic
is set by the SET TERMINAL command. TT2$M_ANSICRT is a subset of
the ANSI standard with no DIGITAL private escape sequences (see
Tables). It is also a subset of
the VT100 family terminals (because TT2$M_ANSICRT is a subset of
TT2$M_DECCRT) and the VT100. Terminals with this characteristic
must provide a display of at least 24 lines, each with 80 columns.
|
TT2$M_APP_KEYPAD
|
Notifies application programs
of state to set the keypad to when exiting.
|
TT2$M_AUTOBAUD
|
Automatic baud rate detection
is enabled. This characteristic
allows the baud rate to be set automatically when you log in. (The
baud rate is set when one or more carriage returns are entered during
the login procedure.) Terminals are set to a permanent speed of
9600 baud. If TT2$M_AUTOBAUD is specified, the permanent speed must
not be changed while this characteristic is in use on a given terminal
line. See
Autobaud Detection for
additional information on automatic baud rate detection.
|
TT2$M_AVO
|
Advanced video is enabled.
This characteristic provides the terminal with blink, bold, and
flashing fields as well as a full screen of 132 character lines.
TT2$M_AVO is set by the SET TERMINAL command.
Tables lists the valid escape sequences for terminals with
the TT2$M_AVO characteristic.
|
TT2$M_BLOCK
|
Block mode is enabled. This
characteristic is set by the SET TERMINAL command. TT2$M_BLOCK defines
additional ANSI-defined and DIGITAL private escape sequences (see
Tables). Terminals with this characteristic
are capable of local editing and block mode transmission (XON/XOFF
flow control must be honored), and have protected fields. If the
terminal is used for large amounts of block input, TT2$M_ALTYPEAHD
should also be specified.
|
TT2$M_BRDCSTMBX
|
Mailbox broadcasts messages. Broadcast
messages are sent to an associated mailbox, if one exists.
|
TT2$M_COMMSYNC
|
Enables devices such as
asynchronous printers to be connected to terminal ports. Flow control
is handled by EIA modem signals instead of XON/XOFF. Setting TT2$M_COMMSYNC
activates the DTR and RTS signals; data is sent once the DSR and
CTS signals are also present. If either of these signals is not
present, printing stops. When both signals are present again, printing
resumes.
Do not set TT2$M_COMMSYNC on a line connected
to a modem that is intended for interactive use. TT2$M_COMMSYNC
disables the modem terminal characteristic that disconnects a user
process from the terminal line in case of a modem phone line failure.
With TT2$M_COMMSYNC set, the next call on the terminal line could
be attached to the previous user's process. TT2$M_COMMSYNC should also
not be used in combination with XON/XOFF, TT$M_TTSYNC, or TT$M_HOSTSYNC.
TT2$M_COMMSYNC and TT$M_MODEM are mutually exclusive.
|
TT2$M_DECCRT
|
DIGITAL CRT terminal. This characteristic
is set by the SET TERMINAL command for all terminals that are upward-compatible with
VT100 family terminals. TT2$M_DECCRT is a superset of TT2$M_ANSICRT.
Additional ANSI-defined as well as most DIGITAL private escape sequences
are allowed for terminals with this characteristic (see
Tables); maintenance modes, VT52 mode, and
the use of the LED displays are not defined by TT2$M_DECCRT. Not
all VT100 family terminals implement these features. The presence
of the advanced video feature cannot be assumed because it is a
VT100 option. This restricts the use of graphics attributes. However,
the TT2$M_AVO characteristic can be used to determine whether additional
graphic attributes are available.
|
TT2$M_DECCRT2
|
DIGITAL CRT terminal. This characteristic
is set by the SET TERMINAL command for all terminals that are upward-compatible with
VT200 family terminals. TT2$M_DECCRT2 is a superset of TT2$M_DECCRT.
|
TT2$M_DECCRT3
|
DIGITAL CRT terminal. This characteristic
is set by the SET TERMINAL command for all terminals that are upward-compatible with
VT300 family terminals. TT2$M_DECCRT3 is a superset of TT2$M_DECCRT2.
|
TT2$M_DECCRT4
|
DIGITAL CRT terminal. This characteristic
is set by the SET TERMINAL command for all terminals that are upward-compatible with
VT400 family terminals. TT2$M_DECCRT4 is a superset of TT2$M_DECCRT3.
|
TT2$M_DIALUP
|
Terminal is a dialup line.
Used by LOGINOUT for the disable dialup control.
|
TT2$M_DISCONNECT
|
Allows terminal disconnect
when a hangup occurs (that is, when modem
signals are lost, when the DCL commands DISCONNECT or CONNECT/CONTINUE
are entered, or when the BREAK key is pressed on a terminal that
has the TT2$M_SECURE characteristic). These terminals are created
as VTAn:. (Refer to the description for the
DCL command CONNECT/DISCONNECT in the HP OpenVMS DCL Dictionary.)
|
TT2$M_DMA
|
Direct memory access (DMA)
mode. This characteristic enables the use of DMA mode for asynchronous
DMA multiplexers. It is ignored by non-DMA controllers.
|
TT2$M_DRCS
|
Terminal supports loadable
character fonts. This characteristic is set with the DCL command
SET TERMINAL/SOFT_CHARACTERS.
|
TT2$M_EDIT
|
Terminal edit. This characteristic
is set by the SET TERMINAL command
for all terminals that support ANSI-defined advanced editing functions.
These functions include the ability to insert or delete a line and
the ability to insert or delete characters in an existing line.
Terminals with this characteristic are a superset of TT2$M_DECCRT.
Tables lists the valid escape sequences
for terminals with the TT2$M_EDIT characteristic.
|
TT2$M_EDITING
|
Line editing is allowed.
|
TT2$M_FALLBACK3
|
Output is transformed from
the 8-bit multinational
character set to a 7-bit ASCII character set on terminals that do
not support the 8-bit character set (see
Tables).
|
TT2$M_HANGUP
|
Terminal hangup. Terminal lines
connected through modems are hung up when a process logs out or
is deleted. The state of this characteristic cannot be changed unless
TT2$M_MODHANGUP is enabled or the process has either LOG_IO or PHY_IO
privilege.
|
TT2$M_INSERT
|
Sets default mode for insert
or overstrike at the beginning of each read operation.
|
TT2$M_LOCALECHO
|
Local echo. This characteristic
is used with TT$M_NOECHO.
If both characteristics are set, only terminators and special control characters
are echoed. Use of this mode is restricted to command-line read
operations. Application programs that use the IO$M_NOECHO function
modifier will not necessarily work if TT2$M_LOCALECHO is set. Local
echo is also not compatible with line editing (TT2$M_EDITING).
|
TT2$M_MODHANGUP
|
Modify hangup. If specified,
TT2$M_HANGUP can be modified without privilege. Otherwise, logical
or physical I/O privilege is required.
|
TT2$M_PASTHRU
|
Terminal is in PASTHRU mode;
all input and output data
is in 7- or 8-bit binary format (no data interpretation occurs).
Data is terminated when the buffer is full or when the data that
is read matches the specified terminator. If the characteristic TT$M_TTSYNC
is set, Ctrl/S and Ctrl/Q interpretation does occur.
|
TT2$M_PRINTER
|
DIGITAL CRT terminal with
a local printer port.
|
TT2$M_REGIS
|
ReGIS graphics. The terminal supports
the ReGIS graphics instruction set.
|
TT2$M_SIXEL
|
SIXEL graphics. The terminal
supports the SIXEL graphics instruction set.
|
TT2$M_SECURE
|
For use with nonmodem, nonautobaud
lines. This characteristic guarantees that no process is connected
to the terminal after the BREAK key is pressed. If TT2$M_SECURE
is not set, BREAK is a null key.
|
TT2$M_SETSPEED
|
Set speed. If specified,
either LOG_IO or PHY_IO privilege is required to change terminal
speed. TT2$M_SETSPEED is not supported for LAT devices.
|
TT2$M_SYSPWD
|
System password. This characteristic
specifies that the login procedure should require the system password
before the user name prompt is displayed.
|
TT2$M_XON
|
XON/XOFF control. If a set mode
function is performed on a terminal in the Ctrl/S state, and if
TT2$M_XON is set, output is resumed. Users should note that the
driver will attempt to resume stopped (XOFF) output on the line.
However, restarting the output may not be successful in all cases.
The XON/XOFF feature does not work on all terminals, for example,
the VT220.
|