VT100.net Terminals and Printers Handbook 1983-84

Chapter 3

VT200 Family of Video Terminals


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.

The self-contained VT220 terminal is a monochromatic text terminal that lets you tailor the terminal to your application.

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.

The VT240, a monochromatic text and graphics video terminal, can be upgraded to include an integral modem.

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.

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


Part Number Description
VR241-A Color monitor. Connects to the VT240 system box in place of the standard monochrome monitor. Standard with the VT241.
VT24X-AA Integral modem/auto dialer. Consists of a circuit board installed in the VT240 or VT241 system box. This option allows you to dial up the host through the keyboard and eliminates the needs for a telephone handset or other dialing mechanism.

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.

Part Number Description
BCC02-02 (VT240 series only) 0.67-meter (2-foot) cable for connecting the monochrome monitor to the system box.
BCC02-06 (VT240 series only) 2-meter (6-foot) cable for connecting the monochrome monitor to the system box.
BCC03-06 (VT240 series only) 2-meter (6-foot) cable for connecting the color monitor to the system box.
BCC04-10 3.1-meter (10-foot) EIA cable for connecting the VT200 terminal to a modem.
BCC05-10 3.1-meter (10-foot) EIA cable for connecting the VT200 terminal to a printer.
BC05F-15 5.2-meter (15-foot) 20 mA cable for connecting the VT200 terminal to the host.
BC22D-25 8.3-meter (25-foot) EIA null modem cable for connecting the VT200 terminal to the host.
VT1XX-KF Screen cleaning kit


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.

Figure 3-1 VT220 On/Off Switch and Successful Self-Test Message


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).

Printer does not print.

Terminal display does not resume scrolling.

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

Nothing is displayed on the screen.

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-INi)
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.


Performance Characteristics


VT220 CRT 30.5 cm (12 in) diagonal measure; white, green, or amber phosphor; monochrome composite
VT240 CRT 30.5 cm (12 in) diagonal measure; white, green, or amber phosphor; monochrome composite
VT241 CRT 33 cm (13 in) diagonal measure, P4 phosphor, RGB color composite
Text format 24 lines × 80 characters or 132 characters (keyboard- or host-selectable.)
VT240 Series Graphics format 800 horizontal × 240 vertical addressable points, two bits per point
800 × 480 logical address range for 2:1 picture aspect ratio
Character VT220: 7 × 9 dot-matrix with 2-dot descenders
VT240 Series: 8 × 9 dot-matrix with 2-dot descenders
Character size: 3.35 mm × 2.0 mm (0.132 in × 0.078 in) in 80-column mode
3.35 mm × 1.3 mm (0.132 in × 0.051 in) in 132-column mode
Character set ASCII, U.K. National, Digital Special Graphics, and Digital Supplemental Character Sets (each 94 printing characters). The ASCII and Digital supplemental character sets make up Digital's multinational character set.
Cursor type Keyboard-selectable, blinking block character or blinking underline (text)
Blinking diamond, visible when graphics mode is active (graphics)
Crosshair, visible when graphics input mode is active


General 105-key detachable unit with a 1.9 m (6 ft) coiled cord attached with a 4-pin telephone-type modular connector. Word processing versions and data processing versions are available in multiple languages and country kits.
Key layout 51-key arrangement and sculpturing similar to standard typewriter keyboard with an 18-key auxiliary keypad
Numeric Keypad 18-key numeric keypad with period, comma, minus, enter, and 4 general purpose function keys
Function Keys 36 keys, firmware and software driven


Type Full-duplex, asynchronous (all models)
Interface EIA RS-232-C and 20 mA, both standard
Speeds 75, 110, 150, 300, 600, 1200, 2400, 4800, 9600, 19,200 b/s, keyboard selectable
Parity 7- and 8-bit: Even, odd, mark, space or none, keyboard selectable
8-bit only: Mark and space
Character size 7- or 8-bit, keyboard selectable
Buffer prevention overflow/
Automatic generation of XON and XOFF control codes, selectable in Set-Up mode
Echo Local echo selectable in Set-Up mode

Power Requirements

Line voltage 90-128 Vac RMS single phase, 3 wire;
180-268 Vac RMS single phase, 3 wire (switch-selectable)
Line frequency 47-63 Hz
Current (VT220) 0.48 A RMS at 120 Vac RMS
0.24 A RMS at 240 Vac RMS
Current (VT240 Series) 2.2 A RMS at 90 Vac RMS
1.1 A RMS at 180 Vac RMS
Power consumption (VT220) 60 W, maximum
Power consumption (VT240 Series) 107 W, maximum

Operating Environment

Temperature 10° to 40° C (50° to 104° F)
Relative humidity 10% to 90% noncondensing
Maximum wet bulb: 28°C (82°F)
Altitude: 2.4 km (8,000 ft)

Physical Characteristics


Height 5.0 cm (2.0 in)
Width 53.3 cm (21 in)
Depth 17.1 cm (6.8 in)
Weight 2.0 kg (4.5 lbs)

VT220 Monitor

Height 28.3 cm (11.1 in)
Width 33.3 cm (13.1 in)
Depth 38.7 cm (15.3 in)
Weight 11.8 kg (26 lbs)

VT240 Monitor

Height 29.2 cm (11.5 in)
Width 34.9 cm (13.8 in)
Depth 31.1 cm (12.3 in)
Weight 6.4 kg (14 lbs)

VT241 Monitor

Height 32.4 cm (12.8 in)
Width 38 cm (15 in)
Depth 42.1 cm (17 in)
Weight 16.6 kg (36.6 lbs)

VT240 Series System Box

Height 8.8 cm (3.5 in)
Width 45 cm (18 in)
Depth 30 cm (12 in)
Weight 2.0 kg (4.5 lbs)