Chapter 3

VT200 Family of Video Terminals

Overview

Digital’s newest family of video terminals, the VT220, the VT240, and the VT241, advance the standard set by Digital’s VT100 family of terminals. The VT200 family includes all the universal features of the VT100 family (see Chapter 5) and expands these further by letting you control more of the terminal’s operations. So that you can tailor the VT200 family to your application. Digital has developed a series of user-friendly set-up menus. These menus contain parameters that you can select and change easily. Just enter Set-Up mode, move the cursor to the field of the characteristic you want to change, and press the ENTER key. It’s that simple.

VT220 and VT240 series terminals can be used with any of Digital’s processors. These video terminals can also work with other vendors’ systems. And just like the VT100 family, the VT200 family is fully compatible with Digital’s printers.

VT220 Video Terminal

The VT220 video display terminal is the low-end member of Digital’s new VT200 family of video terminals. This monochromatic text terminal not only includes all the capabilities of Digital’s VT100 family, but gives you more control of the terminal’s operations.

Since the VT220 video terminal provides so much functionality, the unit is totally self-contained. If you connect your VT220 terminal to a printer, such as Digital’s LA50 Personal Printer, you can print the text you’ve created.

The VT220 terminal consists of a monitor and keyboard. The monitor contains a monochrome cathode ray tube and a terminal controller circuit board. Also contained in the monitor are: power supply and monitor board, host serial communications port, and printer port.

VT240 Series Text and Graphics Terminals

The VT240 is a monochromatic text and graphics video display terminal. As the midrange member of the new VT200 family, it incorporates all the features of the VT100 family and the VT220 terminal. You can upgrade the VT240 to include the optional integral modem that supports auto dialing/auto answering functions.

By generating full bit-mapped graphics in Tektronix 4010/4014 emulation, the VT240 supports the industry’s graphics standards. The VT240 also supports ReGIS (Remote Graphics Instruction Set), Digital’s general purpose graphics command language. It allows you to create pictorial data as easily as you can create ASCII text. By connecting this terminal to a graphics printer, such as Digital’s Letterprinter 100, you can reproduce the screen’s content.

The VT240 uses the same keyboard that is used with the VT220 terminal, a monitor, and a system box. The system box contains the power supply, controller board, and electrical connectors.

The VT241 terminal, the high-end member of the VT200 family, is a VT240 with a color monitor, instead of the monochrome one. It offers the same capabilities as the VT240, but with the RGB monitor providing color graphics display. Because the only difference between the VT240 and the VT241 is the monitor, this handbook refers to them as the VT240 series.

Major Features

Each member of the VT200 video terminal family includes all the features listed below:

User-Oriented Features

Universal VT100 features

Has the capabilities of the VT100 family and helps you make a smooth transition from VT100 terminals to VT200 terminals. See Chapter 5.

Plain language set-up in three languages

Makes it easy for first-time as well as experienced users to operate the terminal and control set-up features. Several menus, which can be displayed in English, French, or German, present a group of choices. From these choices, select the operating characteristic you want to suit your particular application.

15 user-programmable function keys

When defined by the host, these keys store a total of 256 bytes to save frequently used commands and character sequences. This feature reduces keystrokes and helps you to improve productivity.

Downline loadable characters

Lets you design and use special character sets, such as Katakana or Scientific, in the terminal to support your individual application. The 94 characters are loaded from the host when needed.

Advanced video features

Characters can be assigned bold, blink, reverse video, and underline highlighting on a character-by-character basis. This aids in formatting, prompting, and highlighting portions of text.

24 lines by 80 or 132 columns

Allows viewing total format for detailed or spreadsheet work so you can preview reports prior to printing. You get the same results on paper as you see on the CRT screen.

Serial printer port

Enables you to connect a printing terminal to generate local hardcopy printout of the VT200 screen. These two devices can share the same communications line for added savings. The printer port will also support other auxiliary devices.

Compose feature

The COMPOSE CHARACTER key creates characters that do not exist as standard keys on your keyboard. This feature helps you to access any character in the multinational character set, even if it is not displayed on your keyboard. See your Owners Manual for more details.

Selective erase

Supports applications where data is entered by filling in the blanks of a form. This allows the host, with one command, to erase selected areas on the screen. This leaves the form intact for the next data-entry sequence.

CRT saver

Blanks the screen after 30 minutes of inactivity, prolonging the life of the screen’s phosphor. The screen display is restored by pressing any key or if the terminal receives a character from the host.

Compatibility Features

EIA and 20 mA interfaces

Both are standard on the VT200 family. With the EIA interface, the VT200 family of video terminals meet industry standards and achieve compatibility with most systems. The 20 mA interface supports long distance operation of the terminal – up to 500 feet away from the host.

Selectable local echo

This feature lets your terminal display on the screen characters transmitted to the host. This means you can use your terminal on non-Digital systems where local echo is not supported by the host.

VT52 and VT100 family compatibility modes

VT200 terminals are compatible with present Digital software, as well as application software developed for the VT52 and VT100 terminals.

Multinational Features

Multiple language keyboards

Keyboard versions are available for many different languages, for example, English, French, German, Spanish, and Italian, as well as others. The language you want to use is selected in Set-Up.

Seven-bit and eight-bit character support

For compatibility with Digital and non-Digital systems, as well as support of multinational character sets.

Ergonomic Packaging

Detachable, low profile keyboard

The keyboard and the monitor can be positioned separately for your comfort. Since the keyboard has a layout that is similar to that of an office typewriter, the transition from office typewriter to terminal is simple. The keyboard exceed European DIN standards for comfort and ease-of-use.

Nonglare screen conforming to industry standards

Enhances the readability of the screen by reducing glare. The screen is available with green, white, or amber phosphors to suit your preference.

Inverted “T” design of cursor keys

Aids in fast, easy entry of editing commands and lets you quickly position the cursor anywhere on the screen.

Tilt mechanism button (VT220 and VT240 only)

Provides 30 degrees of adjustable tilt so you can adjust the viewing angle of the monitor to suit your preference.

Brightness and contrast controls

Adjust brightness and contrast of the display screen for the best viewing level.

Easy Serviceability

Customer installable

Saves you time and money.

Built-in self-test diagnostics

Reduces the time required to isolate and repair faults.

Screen Attributes

Digital’s VT200 family of terminals allows a standard screen display of 24 lines by 80 or 132 characters. For the VT220, individual characters are based on a seven-by-nine dot-matrix, while for the VT240 Series it is based on an eight-by-nine dot-matrix. These provide clear, crisp text displays.

Operating Modes

The VT200 family has the following operating modes, each selectable via Set-Up from the keyboard or via escape sequences from the host.

• VT200, 7-bit Control Mode executes standard U.S. ANSI functions. This is the default mode of operation.
• VT200, 8-bit Control Mode executes standard ANSI functions. It is used in 8-bit communications environments.
• VT100 Mode is an ANSI mode that emulates a VT100 terminal. It is used for strict compatibility with Digital’s VT100 family of terminals. The Digital multinational character set is not supported in this mode.
• VT52 Mode executes Digital private, not ANSI, functions. Use this mode in conjunction with applications designed for Digital’s VT52 terminal.
• 4010/4014 Mode is a graphics mode used with the VT240 series to display software applications programs designed for Tektronix 4010/4014 terminals.
• ReGIS Graphics Mode is available only for VT240 series operation. It can be entered directly from the VT100 or VT200 modes using commands from the keyboard or host. The VT240 series terminal uses ReGIS graphics mode with software application programs designed for Digital’s VT125 terminals.

These operating modes are described in detail in the VT220 and VT240 Programmer’s Reference Manuals.

Options

Accessories and Supplies

The following VT200 family accessories, supplies, components, and spares are available for the VT220 and VT240 series video terminals. Check with your sales representative or Digital’s Installed Base Group for the latest information.

Maintenance

The VT200 family does not require any preventative maintenance. You can clean the outside of the cabinet occasionally by using a soft cloth dampened with a mild detergent, not a solvent. Monitor screens are cleaned with Digital’s screen cleaning kits. Before cleaning the terminal, Digital recommends that you turn off and unplug the terminal.

Self-Test

The VT220 and VT240 Series terminals automatically perform a self-test each time they are turned on. To see and hear that the terminal is operating properly:

1. Set the monitor’s brightness and contrast controls to the midrange position.
2. Press the power switch to on. Allow time for the terminal to warm up.
3. The terminal will beep and the screen will display the image “VT220 OK” or “VT240 OK”. The latter is also seen for the VT241 terminal.

Operator Troubleshooting Checklist

The following is a list of possible operating problems that may be encountered by VT200 family terminal users and the most common solutions to these problems.

Terminal does not power up when the power switch is set to 1 (on).

• Power cord not plugged in. – Plug in terminal power cord. Check that wall outlet provides the correct power level.
• Monitor not powered up. – With VT241 terminal, both the monitor and the system box must be turned on.
• Voltage selector switch incorrectly set. – Consult the Installation Guide for the correct setting procedure.

Printer does not print.

• Printer not plugged in. – Make sure that printer is plugged into appropriate power source and that it is turned on.
• Cable disconnected. – Check that the cable connecting the VT200 to the printer is firmly in place.
• Incompatible communications features between terminal and printer. – Check that parity, data bits, and baud rates match.

Terminal display does not resume scrolling.

• If the HOLD light is on, press the HOLD SCREEN key to resume scrolling.

Terminal seems to be locked and does not respond to data sent from the host.

• Clear the terminal using the Clear Comm field in Set-Up.

Nothing is displayed on the screen.

• CRT saver feature may have blanked out the display. – Press any key to restore the image.
• Terminal may be in LOCAL mode. – Change Set-Up feature to ON-LINE.
• Keyboard not plugged into monitor. – Make certain that the keyboard is plugged securely to the monitor.
• Cable to the modem or the CPU may not be attached. – Check the cable connection.
• Low setting for brightness and/or contrast control. – Turn brightness and contrast controls until you see the display.

Additional Documentation

The following documents contain more detailed information about the VT200 family of terminals.

Installation of VDTs – An Operator’s Guide (EZ-WJ9A1)

Describes recommended procedures for installing and using VDT’s to achieve a comfortable workstation environment.

VT220 Owner’s Manual (EK-VT220-UG)

Provides information needed to operate the VT220.

VT220 Programmer’s Reference Manual (EK-VT220-RM)

Describes VT220 character processing and provides the character codes, escape sequences, and control sequences needed to generate terminal control programs.

VT220 Installation Guide (EK-VT220-IN)

Describes the procedures used to install the VT220.

VT220 Programmer’s Pocket Guide (EK-VT220-HR)

Provides a quick-reference summary of programming information.

VT220 Video Terminal IPB (EK-VT220-IP)

Provides a detailed parts breakdown of the VT220. Does not provide part numbers for printed circuit board components.

VT240 Series Owner’s Manual (EK-VT240-UG)

Provides information needed to operate the VT240.

VT240 Series Programmer’s Reference Manual (EK-VT240-RM)

Describes VT240 character processing and provides the character codes, escape sequences, and control sequences needed to generate terminal control programs.

VT240 Series Installation Guide (EK-VT240-IN)

Describes the procedures used to install the VT240.

VT240 Programmer’s Pocket Guide (EK-VT240-HR)

Provides a quick-reference summary of programming information.

VT240 Pocket Service Guide (EK-VT240-PS)

Describes procedures used to troubleshoot and repair the VT240 field replaceable units.

VT240 Video Terminal IPB (EK-VT240-IP)

Provides a detailed parts breakdown of the VT240. Does not provide part numbers for printed circuit board components.

Also of interest are:

PDP-11 and VAX Systems & Options Catalogs

Provide you with the most accurate and up-to-date information on currently available PDP-11 and VAX systems, options, and software products. These customer documents are designed to help you select the right Digital product for your needs. European versions are also available.

If you require information not contained in these documents, contact your local Digital representative, dealer, or distributor.

Specifications

Performance Characteristics

Display

Keyboard

Communications

Power Requirements

Operating Environment

Physical Characteristics

Keyboard

VT220 Monitor

VT240 Monitor

VT241 Monitor

VT240 Series System Box