ON AND OFF THE AIR:
* As the formal nomination of Bill Clinton takes place at the Democratic National Convention tonight (the roll call itself should not begin until all the networks check in at 10 p.m), two networks actually offer some non-rerun fare.
At 8 on Fox (WBFF, Channel 45), a new season begins for "Beverly Hills, 90210," with Brenda and Dylan (Shannon Doherty and Luke Perry) getting together secretly -- and then getting caught by her father.
And at 9:30 on NBC (Channel 2), "Dear John" comes back to the schedule with a new episode, as John (Judd Hirsch) faces financial problems. Watch this one while you can -- the series did not get renewed for the fall.
* James Bond fans have a double-feature in store tonight, as part of cable mogul Ted Turner's all-action counter-programming to the Democratic Convention.
At 8:05 on TBS comes "Thunderball," film No. 4 in the 007 archives, from 1965. Recuperating in a health spa, Bond (Sean Connery) happens upon a key clue to the hijacking of an atomic device from a NATO bomber. He ends up in the Bahamas with Claudine Auger and villain Adolpho Celli.
And at 10:30 we get "On Her Majesty's Secret Service," film No. 6, from 1969, one of the oddities of the Bond series.
Connery had retired from the role and English actor George Lazenby took over in this pretty good adventure yarn that also starred Diana Rigg, a hot commodity at the time because of her leather-jumpsuit role in "The Avengers."
The movie has some great stunt work. But Lazenby turned out to be a one-film wonder, as Connery returned to do "Diamonds Are Forever" in 1971.
* Cable subscribers in Baltimore City and Anne Arundel County have a film treat tonight on the American Movie Classics network, carried as a basic service in those areas.
Stanley Kubrick's big "Spartacus" from 1960 is being screened at 9 o'clock in a restored version being shown in the "letter-box" format.
With the device, the top and bottom of the TV picture appears blocked out. Actually, the technique allows the full width of each film frame to appear on the almost-square TV tube. Once you get used to it, you see a film much more as originally screened.
Kirk Douglas stars as the gladiator who led a revolt of slaves, with Laurence Olivier, Jean Simmons, Peter Ustinov, Charles Laughton and a host of other familiar Hollywood faces. The film won four Oscars.