On 6/14/2010 10:40 AM, Darren New wrote:
> Mike Raiford wrote:
>> given the clean-room requirements and high-resolution photo-etching
>> process.
>
> Except that it's pretty much mostly automated. It's a huge capital
> expense, and then automated after that. And when there's only a couple
> of fabs in the whole world, the amount of business they get pays off the
> fab pretty quickly. Basically the prices are set to make a decent profit
> by the time the fab's technology is outdated.
>

Yeah... I kinda got the clue when I was reminded that the $.05 TTL IC 
also requires the same sort of fabrication. ;)

>> Not heard of GPIB, so I looked it up. Apparently aka IEEE-488 surprised
>
> Wow. Even *I* heard of both of those years ago. :-)
>

I haven't .. IEEE-488 sounded vageuely familiar, but I must have been 
thinking RS-485.

>> they're not using Ethernet or something less obsolete
>
> Which ethernet? Thick? Thin Coax? cat-5? Test equipment like this is
> expected to last decades.
>

Cat 5, Cat 5e, Cat 6 ... one of those, UTP or STP.

Of course, that's just the wire. Some of the stuff I worked on used CAN 
bus over STP Cat 6 cable.. A lot of modern control systems use Ethernet 
to communicate with the host, some even use it to communicate from 
device to device, others use CAN.

-- 
~Mike

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