GNOME Terminal Version 3.44.0 for GNOME 42 can so a pretty good ANSI terminal with a few tweaks:
Preferences
Unnamed
Colors
Built-in schemes: White on black
Built-in schemes: Tango

Nodespy as terminal will be an OK ANSI terminal with those settings.

... Anything is possible if you don't know what you're talking about

--- Mystic BBS v1.12 A47 2021/12/24 (Raspberry Pi/32)
* Origin: Mystic Pi BBS bcw142.zapto.org:23 (21:1/145)

On 06 Aug 2022, bcw142 said the following...

GNOME Terminal Version 3.44.0 for GNOME 42 can so a pretty good ANSI terminal with a few tweaks:
Preferences
Unnamed
Colors
Built-in schemes: White on black
Built-in schemes: Tango

if we're sharing, termux for android with telnet and iconv installed is the nicest portable solution in my opinion.. with:

telnet bbs.host.com | iconv -f cp437

obviously if the bbs handles unicode detection well enough, you could leave out iconv.

but a 40some line bbs message reader on a mobile phone is kinda nice :)

... That's not a bug, it's an undocumented feature

--- Mystic BBS v1.12 A47 2021/12/25 (Windows/32)
* Origin: cold fusion - cfbbs.net - grand rapids, mi (21:1/616)