new part-faulty RAM chips?

[Gordon JC Pearce]

Jules Richardson wrote:
> 
> Does anyone know if the Sinclair Spectrum ever made use of RAM chips 
> that were known to be part-faulty as-new? This was just asked over on 
> another mailing list...

Yes.  The upper 32k were supposed to be 4164s.  There are sets of 
jumpers on board to allow for a couple of different types of chips and 
to switch which "half" is in use.

Naturally, all the chips need to be the same.  I learned this the hard 
way when cannibalising dead Spectrums for bits when I was a skint spotty 
teenager.

Gordon.