Last night's television: Prodigy's passion is far from spent

Alex: A Passion for Life (Channel 4), Micro Men (BBC4), Scrubs (E4)

Sweeping views of golden Cambridge spires against an azure blue sky. An Old Etonian with regulation public-school hair and lurid college scarf sits in a fusty lecture before whizzing, gown flapping in the October breeze, down the Backs on two wheels.

For the first few scenes of Alex: a Passion for Life, you might have been watching any freshers' week documentary. Five minutes in was one of those typical ho-ho-ho-these-poshos-don't-know-how-to-boil-a-kettle scenes, yet with it came a potent reminder of the very atypical nature of this film's subject. "What are these for?" asked the director Paddy Wivell, a touch faux-naively perhaps, pointing at the red cords hanging down from the kitchen ceiling. "Did you pull it? Don't pull it!" panicked Alex, turning away from his tea-making tutorial. "It's my emergency alarm. It says I'm dying."

Alex Stobbs is no ordinary student. In January of last year, the Cutting Edge documentary A Boy Called Alex introduced us to this intensely likeable musical prodigy (not, it has to be said, words you often see together) who thanks to the ravages of cystic fibrosis had to swallow a dinner plate full of pills every day simply to survive. In this sequel, we found him a little more grown up, changed not one jot by his new-found "celebrity" (the original documentary resulted in four marriage proposals, apparently) and embarking on his first term as a choral scholar at King's College. Wivell's film balanced the ordinary details of teenage life – girlfriends, football, Harry Potter – with the extraordinary details of Alex's life – a wardrobe full of medication, twice-weekly care visits from his mother, the constant struggle to keep his weight up by eating eight bags of crisps and 10 Twixes a day (leading to a televisual first in which a dietician rebuked a teenager for not eating enough chocolate) and frequent, devastating, hospitalisations.

This time around, there was less emphasis on Alex's precocity and more on his mortality, thanks in no small part to a magnificent soundtrack of Bach's St Matthew Passion, the work Alex was preparing to conduct at his first professional engagement at Cadogan Hall. "One bad exacerbation could be his last illness," his doctor informed us, grimly. Still, Alex treated his worsening condition with matter-of-fact charm, noting quietly "Oh gosh, look at that!" when blood began to pour out of his feeding tube one morning.

He greeted the epic task of conducting the three-hour, 300-page score with similarly sunny equanimity ("Bloody hell, there's quite a lot to learn!") until, that is, he was given a terse ticking off by his lead violinist. Nothing daunted, the final segment saw him ascend the podium – wan, his neck bobbling above an enormous wonky white dicky bow – to achieve his long-held ambition. Having pulled off the glorious soundscape to deafening applause, he retreated, spluttering painfully, backstage where, too weak to accept the congratulations of his family, he shushed them into cowed silence. At once remarkable and unbearable to watch.

Also set in Cambridge was Micro Men, a stand-alone drama about friends turned rival inventors Clive Sinclair and Chris Curry, who brought about the home computing boom in late Seventies and Eighties Britain, with the ZX Spectrum and BBC Micro respectively. For a piece billed as "affectionately comic", it came across as a particularly unaffectionate, even snarky retelling, poking fun at such oh-so-tasteless period markers as oxtail soup, floppy collars, Duran Duran and Alan Sugar's mid-Eighties bouffant (actually, they can poke away at that) and reducing the two pioneers to little more than typically British eccentrics tinkering in sheds.

As Sinclair, Alexander Armstrong, with an egghead and a stick-on orange beard, resembled a rather irascible garden gnome, speaking with a Blackadder-inflected slithery hiss of a voice ("It looks like it was built by a blind Bulgarian bricklayer!" was one particularly plosive outburst). As Curry, Martin Freeman was, well, Martin Freeman-esque as usual, perhaps with a touch of hangdog Tim from The Office. Leaving aside the fact that there is something fundamentally undramatic about watching people build circuit boards (even if it is against the clock), there's a good story in here somewhere, providing a fascinating snapshot of a pre-PC, pre-internet era. A child of the Eighties, I couldn't help thinking that Sir Clive, the man who brought Hungry Horace to the masses – bad tempered, loopily single-minded and frequently misguided he may have been – deserved a little better.

Finally, welcome back Scrubs, still in fine fettle as it embarks on its eighth season. This time there's a new chief in the shape of Dr Maddox, a brittle arachnophobic of the "treat 'em and street 'em" school, played with aggressive zeal by Courteney Cox, not quite vanquishing the ghost of Monica from Friends. There are new interns, too, of whom the hilariously abrasive Denise (Eliza Coupe) is currently my favourite, her idea of a bedside manner being to snap "your jaundice makes you glow", while looking in the other direction. Otherwise, it's more of the same blend of sentimentality and surrealism – JD still has verbal diarrhoea, his dysfunctional bromance with Turk reaches new levels of weirdness, Elliot is even more horribly self-involved and Dr Cox still can't smile. It's good to have them back.