In my experiance, very early chips used a purple ceramic with a high thorium
content causing the distinctive color. Unfortunatley, this thorium emits low
level
particles that cause soft errors, which became apparent in the early days of DRAM.
This drove a change in ceramic processing and costs, pointing the way towards
todays plastic packages.
Sellam Ismail wrote:
> On Mon, 19 Nov 2001, John Galt wrote:
>
> > As far as the color, chip collectors refer to that color chip as
> > "purple". If you look at it next to a normal "gray" CerDIP, you can
> > see the difference. Besides, it would not have mattered had it been
> > black. The fact is, it's not the white/gold color of a normal Intel
> > C8080A. The printing on the chip is also somewhat different. My
> > guess is it's a late run C8080A that was put in the same package they
> > used for some of the later C8085AH's.
>
> My questions is: why does this matter? Will researchers 50 years from now
> find the Purple one useful for any sort of study? What makes the Purple
> one special beyond just being a pretty if not questionable shade of
> purple?
>
> Sellam Ismail Vintage Computer Festival
> ------------------------------------------------------------------------------
> International Man of Intrigue and Danger http://www.vintage.org
Received on Mon Nov 19 2001 - 21:16:21 GMT