Editing VT100 (section)

==Variants==
[[File:Vt100-adventure.jpg|thumb|The VT101 was the lowest-cost member of the VT100 family.]]
[[File:VT 131.jpg|thumb|VT131 at the [[Living Computer Museum]]]]
<!-- EDITORIAL NOTE: Year of introduction should be added to each VT100 variant, to provide better historical perspective -->
<!--  -->
{{redirect2|VT102|VT103|the highways|Vermont Route 102|and|Vermont Route 103}}
The VT100 was the first of Digital's terminals to be based on an industry-standard microprocessor, the [[Intel 8080]]. Options could be added to the terminal to support an external printer, additional graphic renditions, and more character memory. The last option, known as the "Advanced Video Option" or AVO, allowed the terminal to support a full 24 lines of text in 132-column mode, increasing from the 14 lines of the unexpanded model when used in 132-column mode. The VT100 became a platform on which Digital constructed several related hardware products.

The VT101 and VT102 were cost-reduced, non-expandable follow-on versions. The VT101 was essentially a base-model VT100, while the VT102 came standard with the AVO and serial printer port options pre-installed. The VT105 contained a simple graphics subsystem known as [[waveform graphics]] which was mostly compatible with same system in the earlier [[VT55]]. This system allowed two mathematical functions to be drawn to the screen superimposed over the normal text display, allowing text and graphics to be mixed to produce charts and similar output.<ref>{{cite manual|url=http://bitsavers.org/www.computer.museum.uq.edu.au/pdf/AA-4949A-TC%20VT55%20Programming%20Manual.pdf|title=VT55 Programmer's Manual|id=AA-4949A-TC|publisher=[[Digital Equipment Corporation]]|date=February 1977|access-date=2022-04-21|archive-date=2022-03-21|archive-url=https://web.archive.org/web/20220321052006/http://bitsavers.org/www.computer.museum.uq.edu.au/pdf/AA-4949A-TC%20VT55%20Programming%20Manual.pdf|url-status=live}}</ref> The VT125 added an implementation of the byte-efficient Remote Graphic Instruction Set ([[ReGIS]]), which used custom ANSI codes to send graphics commands to the terminal, rather than requiring the terminal to be set to a separate less-efficient ''graphics mode'' like the VT105.

The VT131 added [[computer terminal#Block-oriented terminal|block mode]] support, allowing a form to be sent to the terminal and filled in locally by the user, and then sending the contents of the fields in the form back to the host when the form is filled in.<ref>{{cite manual|url=http://bitsavers.org/pdf/dec/terminal/vt131/EK-VT131-UG-002_VT131_Video_Terminal_User_Guide_Oct81.pdf|title=VT131 Video Terminal User Guide|id=EK-VT131-UG-002|edition=2nd|date=October 1981|publisher=[[Digital Equipment Corporation]]|access-date=2022-04-21|archive-date=2022-07-11|archive-url=https://web.archive.org/web/20220711161527/http://bitsavers.org/pdf/dec/terminal/vt131/EK-VT131-UG-002_VT131_Video_Terminal_User_Guide_Oct81.pdf|url-status=live}}</ref>

The VT100 form factor left significant physical space in the case for expansion, and DEC used this to produce several all-in-one stand-alone [[minicomputer]] systems. The VT103 included a cardcage and 4×4 (8-slot) [[Q-Bus]] backplane, sufficient to configure a small 16-bit [[LSI-11]] microcomputer system within the case,<ref name="vt103-ug">{{cite manual|url=http://www.bitsavers.org/pdf/dec/terminal/vt103/EK-VT103-UG-001_VT103_User_Guide_Sep79.pdf|title=VT103 LSI-11 Video Terminal User's Guide|id=EK-VT103-UG-001|edition=First|publisher=[[Digital Equipment Corporation]]|date=September 1979|access-date=2014-05-03|archive-date=2011-08-14|archive-url=https://web.archive.org/web/20110814095851/http://www.bitsavers.org/pdf/dec/terminal/vt103/EK-VT103-UG-001_VT103_User_Guide_Sep79.pdf|url-status=live}}</ref>{{rp|pp65&ndash;72}} and supported an optional dual [[TU58]] DECtape II block-addressable cartridge tape drive<ref name="vt103-ug" />{{rp|pp73&ndash;80}} which could be used like a very slow disk drive. The [[VT180]] (codenamed "Robin") added a single-board microcomputer using a [[Zilog Z80]] to run the [[CP/M]] operating system. The [[DECmate|VT278 (DECmate)]] added a small [[PDP-8]] processor, allowing the terminal to run Digital's [[WPS-8]] word processing software.