You're calling petscii.nw with PETSCIITerm, right here in your browser: the call is in the dock at the bottom of the window. Pick the machine you're calling as on its bar, or with Alt+M.
PETSCIITERM V0.2
petscii.nw
The call opens in PETSCIITerm along the bottom of the window, and stays on the line while you look around the site. Alt+Z there shows every key.