VT320
| Industry | Computer hardware |
|---|---|
| Founded | November 8, 1957 |
| Fate | Acquired by Compaq (1998) |
| Headquarters | Maynard, Massachusetts , United States |
| Products | VT320, VT330, VT340 terminals; VT200 series; VT500 series |
The VT320 is an ANSI-compliant computer terminal introduced by Digital Equipment Corporation (DEC) in 1987. It represents the text-only variant within the 300 series, while the VT330 incorporates monochrome graphics such as ReGIS, Sixel, and Tektronix 4010, and the VT340 extends capabilities to include color display.
Following the VT200 series, the 300 series was developed as a budget-friendly option aimed at competing with VT220 imitators like the Wyse WY-60, which appeared in 1986 featuring comparable specifications along with 4010 graphics at a price of $699, whereas a base VT220 without graphics cost $795. The VT320 was priced competitively at $495, leading Wyse to lower their unit cost to $599.
In 1990, the VT320 was succeeded by the VT420, while the VT340 continued production until the entire series was replaced by the VT500 series in 1994.
Description
Building on the VT200 models, the VT300 series introduced advanced functionality by utilizing increased RAM capacity to store multiple pages locally and facilitate editing directly on the terminal. This allowed users to navigate through several pages—commonly three—modify content, and transmit all updates to the host simultaneously, provided compatible host software was in use. The expanded memory also supported extensive sixel-based storage for custom glyphs and full-screen bitmap graphics.
Each model supported dual sessions either through two MMJ ports or, in the cases of the VT330 and VT340, via a single serial interface employing DEC's proprietary TD/SMP protocol compatible with specific terminal servers. These sessions could be presented stacked or arranged side-by-side vertically or horizontally. Serial connections operated at speeds up to 19,200 bits per second, equivalent to those of the VT200.
The terminals featured multiple character sets tailored for international applications and form graphics: five sets containing 94 characters plus one set comprising 96 graphical characters, including ASCII and ISO Latin variants. Users could substitute any set with custom characters created using sixels. DEC’s National Replacement Character Sets enabled individual character swaps (for example, substituting # with £ for UK keyboards), minimizing the necessity for country-specific hardware versions. While fully supporting ANSI escape codes, these terminals reportedly did not decode standard color sequences except on the VT340.
The display utilized a 14-inch CRT mounted on a tilt-and-swivel base, offering an 800 by 500 pixel resolution and supporting 25 lines of either 80 or 132 columns; typically, the bottom line displayed local status indicators such as caps lock. The VT330 provided four grayscale levels through two bit-planes, whereas the VT340 delivered 16 colors selected from a palette of 4096 using four bit-planes.
In line with DEC’s design principles, the VT300 series was capable of emulating earlier terminals including the VT100 and VT52.