DEC GIGI (VK100)

Introduction

The GIGI (General Imaging Generator and Interpreter), also known as a VK-100, was manufactured by Digital Equipment Corporation and introduced to market in 1981. It was one of DECs approaches of creating an intelligent graphics terminal that was capable of processing complex graphic commands. It was as an answer to other personal computers such as the Apple II. It had built-in BASIC, 8 color bit mapped graphics, at a resolution of 768 X 240 and was based on the Intel 8085 processor. It supported DEC's ReGIS (Remote Graphic Instruction Set) graphics language, and emulated a DEC VT-52 and VT-100 terminal. It connected to a high-quality monitor and was one of the earliest examples of a terminal that is intended to execute code sent by a server. This was a very rare personal computer as not many were widely manufactured.

Technical Data

• Manufacturer: Digital Equipment Corporation
• Model: VK100
• Introduced in: 1981
• Initial price: $1500
• CPU: Intel 8085A
• RAM: 32 kB (16 KB System RAM, 16 KB Video RAM)
• ROM: 28 kB
• Text Modes: 84×24, 42×24
• Resolution: 768 X 240, 8 colors
• Emulation: VT52, VT100
• Interfaces: RS-232C, 20 mA current loop, composite video, printer
• Local Storage: None

ReGIS was a vector graphics markup language developed by DEC for subsequent models of the VT series of terminals. ReGIS supported rudimentary vector graphics consisting of lines, circular arcs, and similar shapes. Terminals supporting ReGIS generally allowed graphics and text to be mixed on-screen, which made construction of graphs and charts relatively easy.

ReGIS was first introduced on the VT125 in July 1981, followed shortly thereafter by the VK100 "GIGI" which combined the VT125 display system with composite video output and a BASIC interpreter. Later versions of the VT series included ReGIS, often with color support as well. This included the VT240 and 241 and the VT330 and 340.

ReGIS replaced an earlier system known as waveform graphics that had been introduced on the VT55 and later used on the VT105. DEC normally provided backward compatibility with their terminals, but in this case the waveform system was simply dropped when ReGIS was introduced.

BASIC

GIGI BASIC is a tailored version of Microsoft BASIC, specifically designed for GIGI. BASIC is provided as a tool to be used in making GIGI an intelligent terminal. For this reason, only a limited amount of user memory is provided with GIGI. It is therefore recommended that applications and instructional programming be done on the host computer as there is no guarantee of source language transportability between the BASIC in this version of GIGI and that provided in the future. Basic programs can have a length up to 7.8 kB. The BASIC interpreter programs could be loaded, saved, and executed via the serial connection from a host computer. GIGI supports two BASIC modes. One mode is called local BASIC. In local BASIC mode, the terminal user is in control of the GIGI BASIC system. The other mode is host BASIC. in host BASIC mode, the host computer is in control of the GIGI BASIC system. Commands and programs come from the host computer, and all input and output default to the host computer, in effect, the local BASIC mode is the one we know from any other computer, and the host BASIC mode gets its instructions from the serial interfaces and writes its output to the serial interface.