Read-only as in KeyFax was literally a broadcast image of Teletext, rather than actual Teletext. That way, people without a compatible set or decoder (everybody

Read-only as in KeyFax was literally a broadcast image of Teletext, rather than actual Teletext. That way, people without a compatible set or decoder (everybody) could watch it. That had the knock-on effect of users not being able to call up a page at will; they had to wait until it was broadcast.