Epson LQ-1500

What the Epson LQ-1500 was

The Epson LQ-1500 was an impact dot-matrix printer distinguished by a 24-pin print head. The 'LQ' designation stood for 'letter quality': the contemporaneous reference 'This is Your Epson Printer' (reprinted by Atari Archives) describes the LQ-1500 as 'the top-of-the-line in Epson dot-matrix printers' and notes that 'its printhead holds 24 pins instead of the standard nine pins which provides it with resolution that is almost three times that of its siblings,' letting it produce 'near-flawless letter-quality characters.' Like other impact dot-matrix printers, it formed each character by driving print wires against an inked ribbon as the head crossed the page.

The 24-pin print head and print speeds

Where Epson's mainstream printers of the period used nine-pin heads, the LQ-1500 used a 24-pin head that formed characters on a 24-by-24 dot matrix, according to Epson's service manual. The denser pin arrangement produced more fully formed glyphs, which is what allowed the near letter-quality output. Epson's documentation lists two principal speeds: 200 characters per second in draft (pica) mode and 67 characters per second in letter-quality mode. The service manual describes draft printing as bidirectional with logic (logical) seeking, so the head printed in whichever direction minimised travel to the next line of text.

Characters, paper handling and copies

Each character set contained 96 regular, 96 italic and 32 international characters, per Epson's user manual. The printer accepted single cut sheets by friction feed, from 7.2 to 14.3 inches wide, and continuous forms by pin feed with an optional tractor unit, from 4 to 16 inches wide. Epson's manual states that it could print an original plus up to three no-carbon copies, a common requirement for the multipart business forms of the era.

Interfaces

Rather than a single fixed port, the LQ-1500 relied on optional plug-in interface cards. Epson's manuals document three types — parallel, serial (RS-232C) and IEEE-488 — with the service manual noting a 2 KB buffer on the interface boards. This modular approach let the printer attach to a range of personal computers, terminals and instrumentation hosts depending on the card fitted.

Command codes and the LQ legacy

The LQ line is closely associated with Epson's escape-code command language. Wikipedia's article on ESC/P notes that its control codes 'are sometimes also referred to as Epson LQ codes, as they were made popular by the Epson LQ series of dot matrix printers,' while cautioning that ESC/P itself was introduced before the LQ printers. Wikipedia's account of dot-matrix printing records more broadly that 'Epson's 24-pin LQ-series rose to become the new de facto standard' for letter-quality impact printing.

Documentation, dating and current status

The authoritative sources consulted here do not give a precise introduction date for the LQ-1500. Contemporaneous documentation places it in the mid-1980s: it is described as a current top-of-the-line model in a 1986 Epson reference, and the Computer History Museum holds Epson publicity photographs dated circa 1987 that list the LQ-1500 among the company's printer models. Epson's own product page now lists the LQ-1500 (model code L502) as discontinued and directs customers to the LQ-2090II as its replacement.

Reference scope

This page records only facts that can be traced to authoritative sources — Epson's manuals and product page, a Computer History Museum record, and reference works. Any specification that could not be sourced is omitted rather than estimated; that includes a precise introduction year, the maximum printable-column count, graphics resolution, and physical dimensions and weight. It is not a buying guide and quotes no pricing or current availability beyond the manufacturer's discontinued status.