[TenTec] Boards with obsolete parts

[Charles P. Steinmetz]

Bob wrote:

>once the product gets outside of the 7 to 10 [year] period,
>frankly you're on your own regardless of the company.
>
>Should any company support a product past these terms, consider them GREAT
>and generous and well meaning.  In many if not most cases, it just won't
>happen in today's economy.

There is one more factor to consider.  During the design phase, a 
manufacturer can usually choose from a number of hardware 
implementations of the conceptual design.  At this stage, it can 
choose parts that are likely to remain available (or for which 
substitutes are more likely to be relatively easily found later on) 
or parts that are unique and not likely to remain available for 
long.  Often the latter parts will be cheaper in the short run, and 
there is also some fascination with using the latest parts -- thus 
there are often both economic and stylistic incentives to think only 
of the short run.

It is not always easy to tell which parts are likely to remain 
available for a long time -- take AC-series CMOS logic as an example, 
which performed well and was heavily promoted, but in the end was 
prematurely abandoned.  But in many cases, it is not so difficult to predict.

IMO, designers/manufacturers who think of the long run at design time 
are to be praised, and those who don't are justly criticized.

Best regards,

Charles