veetee

veetee is a DEC VT terminal emulator for the Linux and Windows desktop. It aims at SmarTerm/Reflection-class compatibility with real DEC terminals — VT52 through VT525 — so that OpenVMS and other legacy DEC hosts, including DECforms, FMS, EDT, EVE/TPU and SMG$ applications, behave exactly as they do on the hardware.

It follows DEC's own documentation and factory Set-Up defaults. Behaviour borrowed from xterm is available only as an explicit option.

Pages

• Getting Started — requirements, installing, building, running
• Windows — the Windows build: what works and how it differs
• Connections — local shell, Telnet, SSH, serial lines, recording sessions
• File Transfer — sending and receiving files with Kermit
• Printing — the printer port: PDF, a real printer, and printing from OpenVMS
• Using veetee — the window, fonts, CRT effects, sound, scrolling, copy and paste
• Set-Up — the terminal's own configuration screens (F3)
• Keyboard — how a PC keyboard maps to the DEC LK401, the keymap editor, key programming
• Terminal Models — what each model emulates and how it identifies itself
• OpenVMS — setting up DCL and applications for veetee, and recording them for testing
• Conformance Testing — unit tests, vttest, esctest2, session scripts and recordings
• Architecture — how the code is organised
• Releases — versions, downloads and packages
• Roadmap — milestones and what is still to come
• Troubleshooting

Status

veetee 1.9.1 was released on 10 October 2026, with fixes for Windows: SSH sessions get the host's output as sent, and the numeric keypad works in EDT whatever the Num Lock state (Windows). 1.9.0 made the Set-Up settings that were stored only act — zero style, transmit rate limit, modem control, overscan, host wake-up and the energy saver (Set-Up). 1.8.0 brought four sessions on a VT520 or VT525, each on its own connection, with session icons (Sessions). 1.7.0 added manual pages and --version. 1.6.0 made Communications Set-Up set a serial line as on the terminal, from Set-Up or from the host (Connections), and gave Printer Set-Up print mode, extent and terminator (Printing). 1.5.0 brought printing and XOFF from the host. If you use LAT, take 1.4.0 or later. was the last, with LAT in 0.8.9 and RFC 2217 proved against ser2net in 0.8.11. vttest passes across the VT100–VT520 menus headless, and esctest2 runs at VT level 5 with every difference from xterm explained against a DEC manual reference.

What 1.0 did not do is written down in Roadmap: printing (since added, in 1.5.0), a third and fourth session (since added, in 1.8.0), and the Set-Up settings that are stored but not applied — fewer now, the serial line's being applied from 1.6.0. From 1.0 the version follows Semantic Versioning.

Features:

• The VT100/VT102/VT52, VT220/VT320, VT420 and VT510/VT520/VT525 feature sets, including VT525 colour, the VT500 character sets, page memory and dual sessions.
• An LK401 keyboard map in a TOML file with a visual editor, VT500 modified-key sequences and VT520 key programming.
• Session recordings that replay through the emulator as tests.
• Original fonts drawn on DEC's own character cells: 10×16 and 6×16 dots on the VT420 and VT500 series, with Greek, Hebrew and Cyrillic, and 10×8 and 6×8 for 48-line screens.
• Telnet, SSH, serial and local connections on Linux and Windows.
• VT420-style Set-Up with saved power-up settings, sounds, smooth scroll and CRT effects.

The per-function status, with a source for each behaviour, is in the compatibility matrix. The project website is veetee.issinoho.com.

veetee is open source under MIT or Apache-2.0; its fonts are original designs under the SIL Open Font License.