Telnet

Classic terminal access. Port 23/tcp.

Clients

Any standard telnet client. For the best experience, pick one that
speaks CP437 and renders ANSI cleanly:

• SyncTERM — the BBS-scene gold
  standard
• NetRunner — popular alternative
• mTelnet — Windows
• tn5250 or plain telnet (limited; no CP437 font)

ANetBBS speaks the telnet binary-data option, so 8-bit clean transit
is on for ANSI escape sequences.

First-time login

You'll see a welcome screen, then a prompt:

(G)uest, (L)ogin, (N)ew user — choice:

Pick N to register. You'll be asked for a username, password,
email, and answer the New User Questionnaire.

Encoding

The session is CP437. The base.html theme talks about codepages —
each user can override per-account from /profile/edit. Default is
fine for almost everyone; non-CP437 only matters if you're trying to
read echomail bodies authored in Latin-1 or UTF-8.

See also: SSH (same UI, encrypted), Web Terminal (same UI,
in a browser tab).