Chuck Guzis wrote:
The "half good" memory dates back long before 256K chips--it goes all
the way back to 16K ones. I've got a batch of Intel 2109s that
differ from each other by a suffix -1 or -2. The idea is that the
suffix indicates which half is good; otherwise the chips are
electrically the same. I remember when the local Intel sales guy
dropped off a bag of the things on my desk and I sorted through them
and found a batch where all 16K worked in my application.
Cheers,
Chuck
------
Billy:
Actually it goes back further than that. Intersil offered the 6002 (a 2K
Dynamic RAM) with options of 1K good. I never saw it on smaller chips like
the 256 byte or the 1K. But it would not surprise me. This was the era
when a new state of the art memory chip was $15-20 each and in very short
supply. A half good part could be very useful in a terminal or small
system. By small, I mean 4K or 8K bytes, typical of many memory boards
available in the early 1970's.
Billy