IBM 5250 Emulation

Network Virtual Terminal Mode

Network Virtual Terminal (NVT) mode allows the operator to communicate with a network gateway (in ASCII) for routing, logon etc, before the full IBM terminal emulation protocol is established. NVT mode is indicated by the absence of the symbol in the status line along the bottom of the window. NVT mode displays an unformatted screen for data entry, allowing basic keyboard functionality as a simple ASCII terminal. In addition to data keys, other recognized keys are:

Clear

clears the screen

Enter

sends a CR to the host

Newline

sends a CR to the host

Backspace

sends a BS to the host

Tab

sends an HT to the host

Once the appropriate details have been entered to establish an IBM host session (which may be automatic), the screen is cleared and switched into full IBM 5250 terminal emulation mode, as indicated by the symbol in the status line.

The Status Line

The last line in the window is used to display status information in the form of symbols and alphanumeric characters. A coloured line separates status information from the rest of the display. Information is displayed in any of six regions within the status line as listed below.

Region

Symbol

Colour

Column

Meaning

1

T

Blue

1

Telnet session running

2

 

 

 

Blue

18

On line (IBM 5250 mode)

 

 

 

3

M

Blue

28

Message waiting

4

^

Blue

48

Insert mode on

5

 

 

 

Red

57

Input inhibited

6

rr/cc or rr/ccc

White

75-80

Row/column cursor position

The meaning of the symbols is as follows:

TIndicates that a Telnet session is running.

Indicates that the current screen is an IBM 5250 screen. This screen will be displayed when you have initiated a Telnet session with the host.

MIndicates that the system has one or more messages waiting for you.

^Indicates that the keyboard is in Insert mode. Already existing characters to the right of the cursor will move to make room for new characters that are entered.

12-5