Robin Gibb claims that "Saved By The Bell" was the first hit record with a drum machine.

Were drum machines already invented in 1969? To my ears, the drums on that song sound like a pre-set rhythm from an electronic organ (or maybe tape loops).

Robin could probably argue that point, however I was in NY from 85-91 and using Roger Linn's machines at the Power Station, which I thought were the first. At least the first that really worked and were on countless hits in the eighties.
Jimmy Bralower was the first expert and arguably the king of drum programming from its inception. I was a kid and it was a great time to be in NY.

Jimmy would probably know the answer to this. Google him.

It's definitely a drum box, not a tape loop.

Lowery organs had these 'boom-tuck-boom-tuck' devices installed from the mid-1960's. I vaguely recall a standalone unit at the time too, something European, but it's name escapes me.

Yes it is possible. They have been around since the thirties believe it or not.Though the first stand alone drum machine did not arrive till the 70s. en.wikipedia.org/wiki/Drum_machine

Seeing Steve Levine later - will ask him (his Third Reich and Roll has been excellent on R2). Also planning a lunch with my engineer from the 70s/80s John Macswith and will grill him. And heard from John Carter (Beach Baby) yesterday - he would know too.

According to Andrew Goodwin's chapter 'Sample and Hold' from 'On Record',

"In 1979 the fairlight computer musical instrument came on the market,"

this was supposed to be the first form of digital sampler in existence after the outdated types such as a Mellotron that triggered Analogue Samples. And all drum machines of any quality post dated this. As far as im aware.

I would thought that it's "Family Affair" by Sly & The Family Stone.

I know no Syndrum was used on Sparks Number One In Heaven album (1979). According to Russel Mael on his sleeve notes to "The Heaven Collection" it was "Keith Forsey and his trusty right foot". Ah that old technology.

Prince's drum programming was superb. He had one of the first LM-1s and used it in recordings from 1980 onwards.