uu27itu: space desktop wallpaper

##title##

Switchable desktops were designed and implemented at Xerox PARC as "Rooms" by D.A. Henderson and Stuart Card in 1986 based upon work by Patrick P. Chan in 1984. This work was covered by a US patent.

Switchable desktops were introduced to a much larger audience by Tom LaStrange in swm (the Solbourne Window Manager, for the X Window System) in 1989. ("Virtual Desktop" was originally a trademark of Solbourne Computer.) Rather than simply being placed at an x, y position on the computer's display, windows of running applications are then placed at x, y positions on a given virtual desktop "context". They are then only accessible to the user if that particular context is enabled. A switching desktop provides a way for the user to switch between "contexts", or pages of screen space, only one of which can be displayed on the computer's display at any given time.

The first platform to implement multiple desktop display as a hardware feature was Amiga 1000, released in 1985. The Amiga moved on to succeed in the consumer and video production market. All Amigas supported multiple in-memory screens displayed concurrently via the use of the graphics co-processor, AKA the "Copper". The Copper was a simple processor who could wait for a screen position and write to hardware registers. Using the GUI implemented in system ROM API's, programs could transparently display multiple independent screens, from non-consecutive memory, without moving the memory. This hardware-based scrolling does not use blitting, but something more like what is sometimes called hardware panning. The video output is simply told (once, or many times) where to display (scanline) and from what screen memory address. A screen can move to any position, or display any portion, by modifying the wait, or fetch position. Typically a single byte value. The Copperlist did need to be sorted in vertical and horizontal wait position in order to function. Note: See http://www.faqs.org/faqs/amiga/books/ for a list of reference material.

The X Window System is unique in that the decoration, placement, and management of windows are handled by a separate, replaceable program known as a window manager. This separation allowed third-party developers to introduce a host of different window manager features, resulting in the early development of virtual desktop capabilities in X. Many of today's X window managers now include virtual desktop capabilities.