VT05

Introduction

The VT05 was DEC's first free-standing CRT computer terminal introduced in 1970. Famous for its extremely futuristic styling, the VT05 presented the user with an upper-case only ASCII character display of 20 rows by 72 columns. The VT05 was a smart terminal that provided cursor addressing using a series of control characters, one of which allowed the cursor to be positioned at an absolute location on the screen. This basic system provided the basis of similar systems in the later and greatly improved VT50 and VT52 series.

The terminal only supported forward scrolling and direct cursor addressing; no fancier editing functions were supported. No special character renditions (such as blinking, bolding, underlining, or reverse video) were supported. The VT05 supported asynchronous communication at baud rates up to 2400 bits per second (although fill characters were required above 300 bits per second).

Internally, the VT05 was implemented using four "quad-sized" DEC modules in a standard form-factor DEC backplane. The cards were mounted nearly horizontally over an off-the-shelf CRT monitor. The keyboard used advanced capacitive sensors, but this proved to be unreliable and later keyboards used a simple four-contact mechanical switch. The VT05's dynamic storage was a PMOS shift register; the delays associated with manipulating the data in the shift register resulted in the VT05 requiring fill characters after each line feed (as compared to contemporaneous hard copy terminals which required fill characters after each carriage return).

The VT05 also had the capability of acting as a black-and-white RS-170-standard video monitor for videotape recorders, cameras, and other sources. The VT05 was equipped with a video input, and could superimpose its text over the displayed video, making it suitable for interactive video systems. The VT05 Alphanumeric Display Terminal, consisting of a CRT terminal and self-contained keyboard, can be used as a peripheral I/O device with a computer or as a stand-alone closed-circuit television monitor. In computer applications, the VT05 (with system software) can be used to compose, edit, and forward messages to the computer; retrieve and update alphanumeric data contained in the computer files; receive instructions and data from the processor; and perform on-line debugging. The VT05 was eventually superseded by the VT50 which itself was quickly superseded by the VT52.