View source for VT11 Graphic Display Processor

The '''VT11 Graphic Display Processor''' was a [[vector graphics]] [[video terminal]] from [[Digital Equipment Corporation|DEC]]. It was a [[UNIBUS]] device, which used [[Direct Memory Access|DMA]] to retrieve [[display program]]s from [[main memory]]. It was intended for use with the [[VR14 CRT]] or the [[VR17 CRT]].

It was capable of displaying text (using a built-in [[hardware]] [[character generator]]), vectors (solid, dashed, and dot-dash), and points (relative and absolute); any displayed item can be set to blink. The screen grid [[resolution]] was 1024x768. The VT11 also supported a [[light pen]].

The VT11 consisted of three [[DEC card form factor|hex-height]] boards: A320 (vector and character generators and [[digital-to-analog converter|D-A convertors]]); M7013 (display processor); and M7014 (UNIBUS interface). They plugged into a custom [[backplane]].

The VT11 used an odd intermediary technique for its character generator; although it was a vector graphics device, for displaying characters, its character generator stored characters as arrays of pixels. To display a character, it did a [[raster]]-like scan over a small part of the screen, and displayed the character in much the same way a raster display does, although the raster scan used vertical strokes, not horizontal, as in a normal raster display.

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==External links==

* [http://www.bitsavers.org/pdf/dec/graphics/VT11/ VT11] - documents on [[Bitsavers]]
* [http://www.bitsavers.org/pdf/dec/graphics/VR14/ VR14] - documents on Bitsavers

[[Category: UNIBUS Display Controllers]]