Date   : Wed, 18 Oct 2006 20:55:27
From   : Richard Gellman <splodge@...>
Subject: Re: [OT] Would anyone happen to have a 4116 dram chip

Jules Richardson wrote:
>> He later told he he had found that all the chips were faulty, but
>> only in
>> the top 4K(?) where they were masked by the ROM. So Sinclair was buying
>> faulty chips to keep the price down.
>>
>> Or is that another urban myth?
>
> Consumers could definitely buy them at one point; it was the cheapest
> way to get RAM back when it was serious money just for chips with a
> capacity of few kbit. Intel certainly did it. This would be late 1970s
> though, a few years before the Spectrum's time - but given Sinclair's
> ability to cost-cut wherever possible it wouldn't surprise me if he
> tried it for the speccy, assuming that RAM suppliers still even sold
> half-dead parts.
I can confirm that Sinclair did indeed engage in this practice. Though
it was an entire half of the RAM chip that was faulty, as indeed they
were cheaper to get a hold of.  Top half of the chip I believe. Or
rather, the top half of the chip *contained* faults at one or more
addresses. As long as the bottom half was fault-free, it was good to go
for Sinclair.

This obviously works because only the working part of the chip is
needed.  Must've confused a few people when they opened their speccys...

"Uh.. this 48k machine is fitted with 96k of RAM!?!?"

-- Richard