The Sony AG-7E, dubbed the 'Betastack', was a bizarre electromechanical contraption that bolted onto the front of Sony's once highly-regarded top-loading SL-C7 Betamax VCR, Alien 'face-hugger' style.
However, instead of implanting a seed within its host organic being, 1981's Betastack was an auto-changer that fed a sequence of tapes into its host machine. The idea was that you would slot up to three cassettes into the mechanism - plus the one in the deck itself. When one tape finished, it was ejected and the next was lifted into position.
A cult classic
Although it didn't sell well, Betastack has evolved into a cult classic - as have some of the obscure 'sell-through' horror and gore movies that were available in the early-80s heyday of the Betamax format. You can even find video clips of the device 'in action' on YouTube.
Second-hand Betastacks are rare, and tend to get snapped up quickly on eBay - the demand comes from a surprisingly-large community of dewy-eyed Betamax nostalgiacs. Interestingly, until the coming of hard disk playouts, TV broadcasters used 'robots' that did a similarly Heath Robinson-esque job to the Betastack.
These giant machines, designed for unattended operation, would pluck tapes containing ads from a rack and insert them into professional Betacam SP players. Ironically, the Betacam standard - still used by broadcasters today - was derived from Betamax!
This article first appeared in Home Cinema Choice (issue 149).