Using veetee

Using veetee

The window

The terminal page is drawn like a DEC CRT, with the proportions of the model's screen, pixel fonts, dot stretching and scan lines. The window menu has:

• Phosphor — white (P4), green (P1) or amber (P3); --phosphor chooses it at start
• Open Second Session — a second connection to the same destination (see below)
• Mark Checkpoint — a named point in the session recording (see Connections)
• Keyboard Map… — the keymap editor (see Keyboard)
• Full Screen
• About veetee

Fonts and screen proportions

Each model family draws with fonts on its own character cells, like the hardware:

Models	Screen	80 columns	132 columns
VT52, VT100, VT102, VT220	4:3; each dot row is two scan lines	10×10 dots	6×10 dots
VT320, VT420, VT510, VT520, VT525	800×400 pixels of 1:1.4; one scan line per dot row	10×16 dots (24 lines), 10×10 (36 lines), 10×8 (48 lines)	6×16, 6×10, 6×8

The VT420 cell sizes are those of EK-VT420-RM table 5-5. The 10×16 and 6×16 fonts are drawn by hand and cover DEC Special Graphics, Supplemental and Technical, ISO Latin-1, Latin-2 and Latin-5, Turkish, Greek, Hebrew and Cyrillic; the smaller cells are resampled from them so that separate strokes stay separate. 132-column mode switches to the narrow font rather than squeezing the wide one, and a 36- or 48-line screen keeps the page width and uses shorter cells.

Double-width and double-height lines are drawn by doubling dots, and soft fonts (DECDLD) are drawn from the host's own dot patterns.

The VT525 model draws in colour; the host can assign normal and alternate text colours and load its own 16-colour map. Hosts can also choose a blinking or steady, block or underline cursor (DECSCUSR) and name the session: a VT520 session name (DECSWT) becomes the window title.

Dual sessions

Like a VT420 or VT520 with two communication lines, a veetee window can hold two sessions, each with its own connection and its own terminal state: pages, character sets, UDKs, soft fonts, status line and Set-Up.

• Start with --sessions 2, or choose Open Second Session from the window menu. The second session connects to the same destination as the first.
• The window splits horizontally, with a title bar over each session showing its number and name. The window title follows the active session.
• F4 (the Session key) moves the keyboard to the other session; clicking a session does the same. A host can make its session active with DECES.

Status line

Below the page is the VT420 indicator status line, in reverse video. From left to right it shows the printer state, Hold Screen while output is held, Locked while the keyboard is locked, the page number and the cursor position (line, column).

Host applications can replace it with a host-writable status line (DECSSDT/DECSASD), as DECforms and some SMG$ applications do.

Screen size and page memory

The VT420 model has page memory: six 24-line pages by default. A host can select 25, 36, 48, 72 or 144 lines per page, and 24, 36 or 48 lines on the screen. When the page is longer than the screen, the view follows the cursor (DECVCCM), and SU/SD pan through the page as on a real VT420. Ctrl+↑ and Ctrl+↓ pan the view yourself; Ctrl+End and Ctrl+Page Down look at the previous and next pages.

Hold Screen

F1 or Pause toggles Hold Screen. veetee stops reading from the host, so flow control holds the output back without losing any of it. Press the key again to continue.

Copy and paste

• Drag to select. Double-click selects a word — VMS file specifications such as DKA0:[SYS0.SYSCOMMON]LOGIN.COM;1 count as one word. Triple-click selects a line.
• A selection goes to the primary selection, so middle-click pastes it.
• Ctrl+Shift+C copies to the clipboard; Ctrl+Shift+V pastes.
• Both are also on the right-click menu.

DEC line-drawing and special characters are copied as their Unicode equivalents. Lines that were joined by autowrap are copied without a line break.

Answerback

Ctrl+F5 (or Ctrl+Break) sends the answerback message.

Not yet available

Set-Up (F3) and Print Screen (F2) show a notice for now; the bell, key click and DECPS tones are not played yet, and there is no smooth scrolling or CRT glow. These are the rest of milestone M7; see Roadmap.