PCB was first written by Thomas Nau for an Atari ST in 1990 and ported to UNIX and X11 in 1994. Initially PCB was not intended to be a professional layout system but as a tool for individuals to do small-scale development of hardware.
The second release 1.2 introduced user menus. This made PCB easier to use and increased its popularity.
Harry Eaton took over PCB development beginning with Release 1.5, although he contributed some code from Release 1.4.3
A carpet is a textilefloor covering consisting of an upper layer of pile attached to a backing. The pile is generally either made from wool or fibers such as polypropylene, nylon or polyester and usually consists of twisted tufts which are often heat-treated to maintain their structure. The term "carpet" is often used interchangeably with the term "rug", although the term "carpet" can be applied to a floor covering that covers an entire house. Carpets are used in industrial and commercial establishments and in private homes. Carpets are used for a variety of purposes, including insulating a person's feet from a cold tile or concrete floor, making a room more comfortable as a place to sit on the floor (e.g., when playing with children or praying in Arabic culture) and adding decoration or colour to a room.
Carpets can be produced on a loom quite similar to woven fabric, made using needle felts, knotted by hand (in oriental rugs), made with their pile injected into a backing material (called tufting), flatwoven, made by hooking wool or cotton through the meshes of a sturdy fabric or embroidered. Carpet is commonly made in widths of 12 feet (3.7m) and 15 feet (4.6m) in the USA, 4m and 5m in Europe. Where necessary different widths can be seamed together with a seaming iron and seam tape (formerly it was sewn together) and it is fixed to a floor over a cushioned underlay (pad) using nails, tack strips (known in the UK as gripper rods), adhesives, or occasionally decorative metal stair rods, thus distinguishing it from rugs or mats, which are loose-laid floor coverings.