VT100.net Terminals and Printers Handbook 1983-84

Chapter 11

LQP02 Letter-Quality Printer


The LQP02 is a desktop, full character impact printer. It uses daisywheel technology to produce printed copy much like that from your office typewriter. This makes it ideal for such word processing applications as business correspondence and formal documents.

While designed for use with all of Digital's personal computers, workstations, and video terminals, the LQP02 letter-quality printer is also supported on any Digital processor running the RT-11, RSX-11M, RSX-11M-PLUS, RSTS/E and VME operating systems.

The LQP02 can even be used for applications that require graphics output, such as pie and bar charts, and line graphs. This capability is made possible by Digital's new DaisyAids software package, which can be purchased separately. DaisyAids is specifically designed for the LQP02 when used in conjunction with Digital's DECmate II and Rainbow 100, running the CP/M™ operating system.

There are two models of the LQP02 letter-quality printer.

Major Features

The LQP02 letter-quality printer's main features are:

Printing Features

The LQP02 letter-quality printer offers full character letter-quality printing.

Figure 11-1 LQP02 Print Sample

Letter-Quality Printing

LQP02 technology provides letter-quality output at the rate of 32 characters per second. This is suitable for professional-looking correspondence. Printing is accomplished through a bidirectional technique in which the printwheel seeks the shortest distance to the next printable character, rapidly skipping over blank spaces.

Shadow Bolding

Figure 11-2 LQP02 Shadow Bolding

A new feature called "shadow bolding" makes shadow bolded print much more visible than normal bold print. In this technique, characters are struck twice as in normal bolding. But unlike normal bolding, the second strike is slightly offset from the first, resulting in a shadow image.

Character Sets

Changing character sets or type styles is as easy as changing the printwheel. You can select from: UKN Letter Gothic 12, WP Courier 10, WP Pica 10, WP Prestige Elite 12, ANSI OCR-B 10, WPS Boldface Italic PS, Dual Courier 10, European Courier 10, and Greek/Math, as well as others.

With the LQP02, character size can be changed from 10 to 12 characters per inch. When using 10 characters per inch, you can fit 132 columns on legal-sized paper. With 12 characters per inch, 158 columns will fit on legal-sized paper.


The LQP02's sheet feeder option handles regular office stationery in standard, legal, and European sizes. The adjustable form tractor option handles fanfold paper from 7.6 centimeters to 38.1 centimeters (3 - 15 inches) wide, and prints up to 34.3 centimeters (13.5 inches) across.


Part Number Description
LQPX2-SF Dual-tray cutsheet feed; two trays automatically feed pre-cut paper in either portrait or landscape fashion. Front tray accommodates lengths from 26.9 cm to 36.8 cm (10.6 in - 14.5 in), while back tray holds 19.8 cm to 36.8 cm (7.8 in - 14.5 in). Range of widths is between 17.0 cm and 30.5 cm (6.7 in and 12 in)
LQPX2-AA Forms tractor handles fanfold paper between 7.6 cm and 38.1 cm (3 to 15 in) wide
LQPX2-SW Serial interface switch enables better allocation of printing resources. One LQP02 can be shared between two systems in an environment where printing needs are light. Where there is a higher demand for printed documents, two printers can be connected to one system and switched back and forth as needs dictate.
LQPX2-FB Acoustic cover with 120 Vac fan that reduces noise and fits over printer and forms tractor
LQPX2-FD Acoustic cover with 240 Vac fan that reduces noise and fits over printer and forms tractor
LQPX2-FJ Acoustic cover that reduces noise and fits over printer and sheet feeder.
DF01-A Acoustic telephone coupler, 300 b/s with combination EIA (RS232-C) and 20 mA current loop cable
DF02-AA Direct, connect, Bell 103J equivalent, 300 b/s, full duplex, asynchronous modem with EIA RS232-C interface.
DF03-AA Direct, connect, Bell 212A equivalent, 200/1200 b/s, full duplex, synchronous, asynchronous modem with EIA RS232-C interface

Accessories and Supplies

The following accessories, supplies, components, and spares are available for the LQP02 letter-quality printer. Check with your sales representative or Digital's Installed-Base Group for the latest information.


Part Number Description
LQP02-KA 6 high-quality impression multistrike film ribbons. Single loop, sensor stops printer at ribbon's end before characters are lost.
LQP02-KB 6 continuous-loop nylon ribbons. Use until desired type quality can no longer be obtained.


Part Number Description
LQP02-MB Printwheel, UKN Letter Gothic 12
LQP02-MD Printwheel, WP Courier 10
LQP02-ME Printwheel, WP Pica 10
LQP02-MF Printwheel, WP Prestige Elite 12
LQP02-MH Printwheel, Bilingual Courier 10
LQP02-MJ Printwheel, Bilingual Prestige Elite 12
LQP02-MK Printwheel, Bilingual WP Orator 90% 10
LQP02-ML Printwheel, ANSI OCR-B 10
LQP02-MN Printwheel, England Pica 10
LQP02-MP Printwheel, England Courier 10
LQP02-MR Printwheel, England Prestige Elite 12
LQP02-MS Printwheel, WP Letter Gothic 12
LQP02-MT Printwheel, WP Gothic 15
LQP02-MV Printwheel, ASCII-96 Prestige Elite 12
LQP02-MW Printwheel, WPS Boldface PS
LQP02-MX Printwheel, WPS Title PS
LQP02-MY Printwheel, WPS Thesis PS
LQP02-MZ Printwheel, Nederland Prestige Elite 12
LQP02-NA Printwheel, WPS Boldface Italic PS
LQP02-NB Printwheel, Nederland Pica 10
LQP02-NC Printwheel, Dual Courier 10
LQP02-ND Printwheel, European Courier 10
LQP02-NE Greek/Math
H9850-HE Heavy-gauge vinyl dust cover, charcoal brown with Digital logo
H9850-AT LQP02 stand
H9850-FA Paper caddy with 4 5.1 cm (2 in) swivel casters for transporting printer paper, 40 cm wide × 29.8 cm deep (15¾ in × 11¾ in)
STKIT-AA Systems Terminal Tool Kit (60 Hz)
STKIT-AB Systems Terminal Tool Kit (50 Hz)
Figure 11-3 LQP02 Daisywheels
UKN Letter Gothic 12
WP Courier 10
WP Pica 10
WP Prestige Elite 12
Bilingual Courier 10
Bilingual Prestige Elite
WP Orator 90% 10
England Pica 10
England Courier 10
England Prestige Elite 12
WP Letter Gothic 12
WP Gothic 15
ASCII 96 Prestige Elite 12
WPS Boldface 12
WPS Title PS
WPS Thesis PS
Nederland Prestige Elite 12
WPS Boldface Italic PS
Nederland Pica 10
Dual Courier 10
European Courier 10

Operator Features

Front Panel Indicators and Switches

A total of eight controls and indicators are found on the front panel of the LQP02 letter-quality printer.

Figure 11-4 LQP02 Controls and Indicators

Power Indicator

The green POWER light indicates the operating state of the printer. The light is on when the printer is on-line and ready to print or is printing. The light is off when the printer is off-line.

DSR (Data Set Ready) Indicator

The green DSR light stays on when the DSR line is activated and the printer is under modem control. When not under modem control, the light is not on.

Printer Error

The red PRINTER ERROR light blinks when a mechanical or electrical problem is detected by the printer. During a PRINTER ERROR, an audible signal is sounded, and the printer will stop printing.

Ribbon Out

The red RIBBON OUT light blinks when the printer runs out of film ribbon. The RIBBON OUT indicator does not indicate the end of a cloth ribbon, or the breaking or jamming of any type of ribbon. When the end of a film ribbon is detected, a buzzer sounds and the printer stops printing.

Paper Out

The red PAPER OUT light blinks, a buzzer sounds, and printing stops when the printer is out of paper, or if the paper is jammed.

Pause Indicator

The yellow PAUSE light blinks and printing stops when the PAUSE switch is on.

Pause Switch

The PAUSE switch is a rocker switch. When the top is pressed, printing stops and the pause light starts blinking. When the bottom is pressed, printing resumes with no loss of characters and the pause light stops blinking.

Activate the PAUSE switch when changing ribbons or daisywheels, or rolling the paper to the top of the form.

Form Feed Switch

When not printing, and the top of the FORM FEED switch is pressed, the paper advances a page.

Printer Controls

The LQP02 letter-quality printer has eight printer controls.

Figure 11-5 LQP02 Printer Controls

Paper Bail

This holds the paper against the platen. The two handles permit adjustment of the entire bail from either side of the printer.

Paper Thickness Lever

The paper thickness lever adjusts spacing between the daisywheel and the platen. For an average thickness, place this lever in the forward position. For thicker sheets, envelopes, and multipart forms, move this lever toward the back of the printer.

Edge Guide

This movable edge eases paper insertion at any point along the platen.

Card Guide

This establishes a printer reference line for the top edge of the paper and assists in locating the vertical printing position. Paper should never be pulled against the card guide, but rather the formfeed switch should be pressed or the platen knob turned.

Column Indicator

This indicator assists you in positioning paper on the platen and locating the horizontal printing position.

Paper Release Lever

The paper release lever controls pressure applied to the paper by the cradle rollers underneath the platen. Backward movement of this lever holds the paper tightly against the platen. Forward movement releases the paper.

Platen Knobs

Turning the right knob clockwise or the left platen knob counterclockwise advances the paper through the printer.

Text Recovery Switch

When activated, this switch informs the status protocol handler of the printer's condition. This means that you can signal the host of a printer problem that may cause the loss of text.

Printer Configurations

The LQP02 Letter-Quality Printer contains two banks of configuration switches, which are set for worldwide system operation without a modem. If you need to change the configuration, the switches required for this operation are located on the back of the LQP02. Note: Before resetting the switches, check that you have turned the power off.

Figure 11-6 LQP02 Configuration Switches

The switch positions can be easily changed by flipping the position up or down. When the switch is down, it is off. When up, the switch is on. A diagram of the switches can be found underneath the front cover of the LQP02.

Left Switch Bank (SP1)

The left group contains 12 preset switches (SP1-1 through SP1-12). These are factory set at the following:

Baud Rate Select Switches (SP1-1, SP1-2, SP1-3, SP1-4)

These switches select the speed at which the printer transmits and receives data from the host processor. The LQP02 is factory set for 4800 baud.

Table 11-1 Baud Rate Select Switches
Baud Rate Bits per Second SP1-1 SP1-2 SP1-3 SP1-4
75/600 Down Down Down Down
75/1,200 Up Down Down Down
110 Down Up Down Down
134.5 Up Up Down Down
150 Down Down Up Down
200 Up Down Up Down
300 Down Up Up Down
600 Up Up Up Down
1,200 Down Down Down Up
1,800 Up Down Down Up
2,000 Down Up Down Up
2,400 Up Up Down Up
3,600 Down Down Up Up
4,800 Up Down Up Up
7,200 Down Up Up Up
9,600 Up Up Up Up
Parity Enable Switches (SP1-7 and SP1-8)

These two switches select the parity mode.

Table 11-2 Parity Enable Switches
Parity Mode SP1-7 SP1-8
Mark Down Down
Odd Down Up
Space Up Down
Even Up Up
Remaining Left Bank Switches

The table below names the remaining left bank switches and explains their function, and the meaning of up and down position settings. Refer to Figure 11-6.

Table 11-3 Other Left Bank Switches
Switch Function Up Position Down Position
Stop Bits
Selects one or two stop bits for data format. Two stops bits One stop bit
Full/Restricted Modem Control
Indicates the presence or absence of a modem. Full modem control Restricted modem control
RLSD Disconnect Timing
Selects the two second (2 s) timer or 60 ms timer for data channel RLSD (received line signal detector) aborts. 60 milliseconds 2 s timer
Paper Out Enable
Enables or disable paper-out sensor. Disables Enables
Status Inhibit
For system testing, inhibits or enables status transmission for polled requests. Inhibits a status transmission for polled requests until all printer buffers are empty. Enables
Selects self-test operation. Disables Enables formfeed switch to start electronic and mechanical tests of printer operation.

Right Switch Bank (SP2)

The right bank contains eight switches (SP2-1 through SP2-8). Factory settings are indicated by †. See Figure 11-6.

Table 11-4 Right Switch Bank
Switch Name Function Up Position Down Position
SP2-1 Transmitted Data Allows printer to send data to host via I/O connector pin 2. Disables Enables†
SP2-2 Transmitted Backward Channel Data Allows printer to send data to host via I/O connector pin 14. Disables† Enables
SP2-3 Transmitted Backward Channel Signal Prepares a modem to receive a signal. Disables† Enables
SP2-4 Request to Send Prepares a modem to receive a signal. Disables† Enables
SP2-5 Request to Send Off Level Enables/disables send off function. Disables† Enables
SP2-6 Ready for Sending Allows modem to say if it is ready or not to receive data from the printer. Disables Enables†
SP2-7 Backward Channel Ready Selects backward channel ready line. Disables† Enables
SP2-8 Data Signaling Rate Selector Connects data signaling rate selector line to a modem. Disables Enables†

Protective Ground Switch

When a modem is installed in your system, the up position of this switch connects the printer frame to the "protective ground" line (I/O connector pin 1). See Figure 11-6.

Normally, this switch is in the up position with or without a modem. But in other countries, such as Germany or the United Kingdom, local safety regulations require that the switch be in the down position, where the printer ground is not connected to the electrical ground.

Programming Information

The LQP02, like Digital's other receive-only printers, uses escape sequences and features that were standardized by the American National Standards Institute (ANSI). Following the brief description of each escape sequence feature will be the summary of the actual escape sequence required. Detailed information on all LQP02 escape sequences can be found in the LQP02 Printer Programmer's Reference Manual.

Escape Sequences

Some frequently used escape sequences are outlined below. Note: In this section, VAI stands for vertical advance increment and one VAI equals 1/48 of an inch. HAI stands for horizontal advance increment, and one HAI is equal to 1/1200 of an inch.

Table 11-5 Common LQP02 Escape Sequences
Name Function Escape Sequence
Printer Initialization Resets printer to default settings. ESC c
Perform Next Line Forward Advances paper to next line. ESC E
Enter Right Margin Wrap Mode Set right margin wrap mode. ESC [ ? 7 h
Exit Right Margin Wrap Mode Reset right margin wrap mode ESC [ ? 7 l
Enter New Line Mode Set new line mode. ESC [ 20 h
Exit New Line Mode Reset new line mode. ESC [ 20 l
Set Forms Size Pn must be between 1 and 169, inclusive ESC [ Pn t
Set Horizontal Tab at Selective Columns Pn equals the column number. ESC [ Pn1 ; . . . ; Pn16 u
Clearing Horizontal Tabs Clears all horizontal tabs. ESC [ 3 g
Set Vertical Tabs at Selective Lines Pn equals the line numbers. ESC [ Pn1 ; . . . ; Pn16 v
Clear Vertical Tabs Clears all vertical tabs. ESC [ 4 g
Setting Right and Left Margins Pn1 must be less than Pn2. ESC [ Pn1 ; Pn2 s
Setting Top and Bottom Margins Pn1 must be less than Pn2. ESC [ Pn1 ; Pn2 r
Set Underlining Enable underline mode. ESC [ 4 m
Set Underlining Disable underline mode. ESC [ Ps m
Set Shadow Printing Enable shadow printing. ESC [ ? 2 m
Set Shadow Printing Disable shadow printing. Ps equals 0 or null. ESC [ Ps m
Setting VAI and HAI to Numeric Parameters Pnv must be between 15 and 960, inclusive.
Pnh must be between 6 and 768, inclusive.
ESC [ Pnv ; Pnh SP G

Setting HAI and VAI

You can also set HAI and VAI to selective parameters.

Table 11-6 Selecting HAI (ESC [ Ps w)
HAI Ps Characters per Inch
12 Null 10
12 0 10
12 1 10
10 2 12
10 3 12
10 4 12
12 5 10
12 6 10
12 7 10
12 8 10
8 9 15
Table 11-7 Selecting VAI (ESC [ Ps z)
VAI Ps Characters per inch
8 Null 6
8 0 6
8 1 6
6 2 8
6 3 8
24 4 2
16 5 3
12 6 4

Communications Protocols

Communications protocols can also be established by using escape sequences.

Table 11-8 Communications Protocols
Name Function Escape Sequence
Set Status Communication Protocol Polled report request. ESC [ 5 n
Enable brief unsolicited reports and send an extended report. ESC [ ? 2 n
Enable extended unsolicited reports and send an extended report. ESC [ ? 3 n
Disable all unsolicited reports. ESC [ ? 4 n
Send Brief Status Report Printer response: Ps equals 0, printer is ready, no malfunctions detected. ESC [ Ps n
Printer response: Ps equals 3, printer is not ready, a malfunction is detected. ESC [ Ps n
Send Extended Status Report Printer Response: Ps1 equals 0, printer is ready, no malfunction is detected. ESC [ Ps1 n
ESC [ ? Ps2 ; . . . ; Ps2 n
Printer Response: Ps1 equals 3, printer not ready, there is a malfunction detected. ESC [ Ps1 n
ESC [ ? Ps2 ; . . . ; Ps2 n

You should note that Ps2 can be any of the following values:


The LQP02 letter-quality printer does not require preventative maintenance. However, in order to ensure proper operation of your LQP02 printer, keep the following items in mind.

Self-test Procedure

To initiate a self-test procedure:

  1. Check that the power is off and the cover is on.
  2. Insert sheet of paper in horizontal position, as far to the left as it will go.
  3. Move self-test configuration switch (SP1-12) down.
  4. Press top of power switch.
  5. Front-panel lights should blink twice, and carriage should move to the far left.
  6. Press FORM FEED switch once. Red printer-error, ribbon-out, and paper-out lights should blink twice.
  7. Wait a few seconds, and press FORM FEED switch again. Buzzer should sound, printing should start, and forms tractor or sheetfeeder, if installed, should operate.
  8. After at least two lines of printout are obtained, press top of PAUSE switch. Printout should include at least one carriage return, one line feed, and all characters on printwheel.
  9. If the printer passes self-test, you're all set to go. If it doesn't, refer to the next section.

Operator Troubleshooting Checklist

If your printer is not operating, chances are the problem is minor and you can correct it yourself. Listed below are some of the common problems, their probable cause, and the corrective action you can take. Note: Always turn off the printer before you attempt to correct a problem.

Figure 11-7 Voltage Selection Switch

Printer stops or won't turn on (power light off).

Printing stops or won't start (power light on).

Printing stops or won't start (printer error light on).

Power-up failure (power light on, buzzer sounds continuously).

Some characters improperly spaced or positioned.

Characters too close together or too far apart.

Characters not consistently dark.

Figure 11-8 LQP02 Power Switch

Characters not sharp or dark enough.

Parts of characters missing.

Top or bottom of characters missing.

Ribbon breaks or jams.

Perforated paper.

Additional Documentation

The following documents contain more detailed information about the LQP02 letter-quality printer.

Also of interest are:

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


Performance Characteristics

Print speed 32 char/s (letter-quality, Shannon text)
Print technology Bidirectional, full-character, impact
Print density Full character, even density
Character pitch Variable pitch, software selectable (10 char/in default)
Line spacing Variable, includes proportional spacing (6 l/in default)
Vertical slew speed 5 in/s
Buffer capacity 256
Buffer control XON/XOFF


Type Cutsheet or fanfold
Cutsheet 7.6 cm to 34.3 cm (3 to 13.5 in) wide
Fanfold 7.6 cm to 38.1 cm (3 to 15 in) wide
Thickness 0.025 cm (0.011 in) maximum


Baud rates 75, 110, 134.5, 150, 200, 300, 600, 1200, 1800, 2000, 2400, 3600, 4800, 7200, and 9600, full-duplex transmission
Data interface Serial RS232-C EIA standard
Parity 7-bit, odd, even, mark or space

Power Requirements

LQP02-AA 120 Vac, 60 Hz
LQP02-AD 240 Vac, 50 Hz
Power consumption 120 W, average RMS

Operating Environment

Temperature 10°C to 40°C
(50°F to 104°F)
Relative humidity 10% to 90%

Physical Characteristics

Width 63.5 cm (25 in)
Depth 40.6 cm (16 in)
Height 17.8 cm (7 in)
Weight 22 kg (48 lb)