"It's all here." LeMat waved the manual nervously. "The note from MDE Trademarks and Legal. They decided Sacroiliac Neural Induction Device was too much of a mouthful, and SNID was a stupid acronym." He tried another weak grin.
TAP. TAP. TAP.
"So they decided to find a new name. Convened focus groups, the whole bit. And they finally came up with one they liked."
TAP. TAP. TAP.
"They call it the ProctoProd(TM), Jack."
My foot froze in mid-air. "The what?"
"That's how it works." LeMat gulped, took a deep breath, took a long good stare at it, and then looked me straight in the eye and nodded.
"You stick it up your ass and dance, Jack."
--Bruce Bethke, Headcrash
While most interfaces are not quite as inconvenient as the ProctoProd(TM), their limitations do play an important role in defining digital space. Word processors, for example, rely almost wholly on input from a keyboard, while a game might respond better to the use of a joystick. Some spaces aren't possible without specific interfaces; the Apple Macintosh simultaneously popularized the mouse and the graphical user environment. Without the former, the latter would be unwieldy; without the latter, the former would be useless.
On the output end of the interface, tape was long ago replaced by the monitor, which has steadily increased in resolution. Now VR headsets are becoming available; a recent edition of Computer Gaming World carries an advertisement for a VR helmet that retails for approximately $1,000 (which may seem like an exorbitant cost until one compares it with the price of other peripherals, such as laser printers or CD-ROM drives, at their inceptions).