LK201
Introduced inverted-T cursor keys and Compose key in 1982.
The LK201 is a detachable computer keyboard introduced by Digital Equipment Corporation of Maynard, Massachusetts in 1982. It was first used by Digital's VT220 ANSI/ASCII terminal and subsequently by several microcomputers and workstations. Its layout introduced the inverted-T cursor key arrangement and a Compose key, which influenced the design of later keyboards.
- Introduced
- 1982
- Manufacturer
- Digital Equipment Corporation
- Location
- Maynard, Massachusetts
- First used with
- VT220 ANSI/ASCII terminal
- Connection
- 4 position modular connector, 12 volt power, 4800 bit/s asynchronous serial data
- Layout innovation
- inverted-T cursor keys, Compose key
Lore & Background
The LK201 keyboard was designed with a very low profile for ergonomic reasons, especially thin compared to the VT100 keyboard. It added a set of cursor and miscellaneous keys between the main keyboard and the numeric keypad, with cursor keys arranged in the now-standard inverted T. The Compose key allowed typing extended characters using two-stroke mnemonics, such as Compose u " to produce ü, with an LED indicating an ongoing compose sequence. The keyboard connected via a 4-position modular connector carrying 12 volt power and 4800 bit/s asynchronous serial data. At its introduction, the layout differences from the Teletype Model 33 and VT100 were disruptive, but the LK201's key arrangement was emulated by the Model M and became the de facto standard for full-sized keyboards. Today's standard layout differs primarily in restoring the Escape key and reducing the numeric keypad from 18 to 17 keys. The Compose key survived in the European ISO standard but not in the U.S. ANSI standard. Follow-on keyboards from Digital refined the design; the LK421 omitted the middle group of cursor and function keys but included a dedicated Escape key, preferred by many Unix users.
Reader's Guide
The LK201's significance lies in its introduction of the inverted-T cursor key arrangement, which became the standard for essentially all contemporary full-sized computer keyboards. Its layout was emulated by the even more successful Model M keyboard, and through that, it became the de facto standard. The Compose key, while not retained in the U.S. ANSI standard, survived in the European ISO standard. The keyboard's low-profile design was an ergonomic consideration, contrasting with the VT100 keyboard. The LK201's influence is seen in the modern standard layout, which differs primarily in the restoration of the Escape key and a reduction of numeric keypad keys from 18 to 17. Digital's follow-on keyboards, such as the LK421, refined the design, with the LK421 omitting the middle group of keys and adding a dedicated Escape key for Unix users who preferred a narrower keyboard.
Did You Know?
- The LK201 was introduced in 1982 by Digital Equipment Corporation of Maynard, Massachusetts.
- Its cursor keys were arranged in the now-standard inverted T layout.
- The Compose key allowed typing characters like ü using two-stroke mnemonics.
- The keyboard connected via a 4-position modular connector with 12 volt power and 4800 bit/s serial data.
Frequently Asked Questions
What is the LK201?
The LK201 is a detachable keyboard that Digital Equipment Corporation released in 1982. It went on to become one of the most influential input devices of the early personal-computing era.
Who made the LK201 and where?
DEC produced the LK201 from its facility in Maynard, Massachusetts. The keyboard debuted in 1982 as a standalone, detachable unit rather than a fixed part of a computer chassis.
What layout features did the LK201 introduce?
It popularized the inverted-T arrangement for the cursor/arrow keys and added a dedicated Compose key to the layout. Both design choices carried forward into countless later keyboard designs.
What was the LK201 originally designed to pair with?
DEC first paired the LK201 with their VT220 ANSI/ASCII terminal. After that initial pairing, the keyboard found its way onto a range of microcomputers and workstations.
How did the LK201 connect to a host computer?
It used a four-position modular connector and drew 12 volts of power from the host. Data traveled over an asynchronous serial link at 4800 bits per second.
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