The IC-10 was an audio integrated-circuit
power amplifier, created under a marketing agreement
with Plessey, who were to produce the devices for Radionics.
The first batch was scheduled for delivery on 1 June
1968 and the advertising for the IC-10 duly appeared
as a double-page spread in all the usual magazines.
Deliveries of packaging material and instruction leaflets
began on time, and all was set for a June launch.
June arrived - but no ICs: there had been production
problems at Plessey. No - they didn't know how long
these would take to sort out. No, Sinclair couldn't
have even a small delivery immediately - not for an
Since it takes about three months to change advertising,
Sinclair decided not to modify the plans, for surely
the devices would be available by the time the adverts
changed? Eventually, it became apparent that the delay
was going to be prolonged, but orders - and cash - were
flowing in from customers. The delay was lengthy and
it was likely that the customers' payments would have
to be refunded, at considerable expense to the company.
Luckily, Chris Curry - later of Acorn fame - was working
on the design of a miniature FM radio which contained
a small device - the IC-4 - which was wheeled out as
a stop-gap alternative to the IC-10. Each customer who
had ordered an IC-10 received an IC-4 as a free gift
with an apology for the delay and a request to be patient,
since the IC-10 was well worth waiting for. Its true
worth was, however, definitely a matter of opinion,
as Alfred Marks recalls:
It was Clive who first made an integrated
circuit available to the public - the IC-10. Then
an integrated circuit was a miracle, but the IC-10
wouldn’t peak at 3 watts really, and flopped. It was
probable, although only rumour, that the IC-10 was
a product which Plessey were not too happy to have
in their stable, anyway.
(Sinclair & the Sunrise Technology, p.27)
The IC-10 eventually emerged at the end of 1968 and
remained in Sinclair's range until the middle of 1970.