Using
Teletext
SHIFT-F7 will allow the current page to be saved in the current filing system.
Rather than saving a "screenshot" of 1024 bytes, as you might expect, the actual file is a little bit shorter as it is coded in Teletext format. I won't go into all that now, it's a bit in-depth, but if you try to load it back in MODE 7 with *LOAD xx 7C00 then it won't show up correctly.