Inject text alerts into a CATV system

["Robert Green" <ROBERT_GREEN1963@xxxxxxxxx>]

Dad's nearly deaf and is not terribly compliant about keeping his hearing
aid turned up.  Instead, he watches the TV with the set's *sound* turned way
up - we're talking thunderous volume here.  Unfortunately, this means he's
almost completely unaware of his surroundings.

What I would like to is create a fairly low cost HA system that's capable of
putting up brief text messages over the TV so when he's watch March Madness
and someone's pounding on the door and ringing the buzzer, I can send "Front
Door bell ringing" or "phone call" or "smoke detector activated" or
"FIRE!!!" or whatever on the screen so he knows to take some action.

We've already got various phone flashers scattered around the house, but I
would also like to pipe Caller ID info to the screen as well so that he
*knows* who's calling, not just that there's a phone call.  I don't know if
other folks' parents are like mine, but after years of being barraged by
telemarketers, they are as likely just to let the phone ring if they aren't
expecting a call.  It's become a real issue.

I'm still very much in the planning stage and would like to hear from anyone
who's done something similar.  It's complicated by the fact that there are
three TV's he's likely to be watching.

--
Bobby G.