|Release date||October 1970|
The Hazeltine 2000 is possibly the first general-purpose
One advanced feature of the design was the concept of "
The base model displayed 27 lines of 74 characters, uppercase only, while an expansion added lowercase and 80-by-25 layout. This became the standard model and the price was lowered in 1974. The basic system was reimplemented several times using newer electronics as they became available during the 1970s. The
The system was an all-in-one unit with a 12" diagonal green phosphor screen with a 8.5" by 5.75" display area. The system weighed 62 pounds (28 kg) and required at least 24 inches (610 mm) of depth on a desk, and drew a massive 350 W in operation. It required 30 seconds to "warm up", and continually ran a fan to cool the system. Later models first grew to 63 pounds (29 kg) before falling to 57 pounds (26 kg).
In contrast to most glass terminals of the era, the 2000 offered only
Request To Send characters to sent data in order to turn around the communications channel in
The system also had outputs for a printer,
The keyboard could be detached, connecting to the terminal using a 5 foot (1.5 m) 54-pin HDR connector. It had a 51-key typewriter layout main section, along with a
The base-model system had a
A key feature of the 2000 was its ability to be put into "batch mode", either by pressing the appropriate lamp/button on the right of the keyboard, or by sending the appropriate command as ASCII codes from the host computer. When the terminal was in this mode, the batch lamp/button was turned on.
In batch mode, typing on the keyboard was not immediately sent to the host, but was instead buffered into the 2 kB of internal
Batch mode was normally used in conjunction with a separate feature, foreground/background mode. This system allowed the text on the screen to be displayed at normal intensity, foreground, or a reduced intensity, background. The mode for every character on the screen was held in the buffer, so foreground and background data could be displayed anywhere on the screen.
The key feature of this concept is that common commands, like clear screen, could be issued to clear only the foreground or background data, and batch mode sends only sent the foreground. In practice, the host computer would send a stream of data in background mode to lay out a form, sending spaces in foreground mode to indicate input areas. Once the form was complete, it would switch back to foreground mode and turn on batch.
Once sent up in this fashion, the user's input would only be into those portions of the screen that were in foreground mode, and only their entries would be sent back to the host. Additionally, the cursor keys and
Like the wide variety of smart terminals that followed, the 2000 used an
SO to trigger a transmit in batch mode,
US (unit separator) to indicate following data was in foreground mode,
EM (end of medium) to indicate background,
FS (form separator) to clear the screen, or
GS to clear just the foreground.
The command set also included basic editing and cursor positioning typical of other smart terminals.
CD2 sent the cursor to the "home" position in the upper left,
CD3 deleted the line, and
SUB inserted a blank line below the cursor position.
DC1 allowed the cursor to be sent to an indicated location on the screen by following it with two ASCII characters where the character code indicated a number. For instance, the
NUL, ASCII code 0, would send the cursor to row or column 0. To avoid problems in transmission, the pattern repeated at 32,
Space, so that the Y coordinate could be send using the characters in the