Challenge: Motorola SC85370P

I know exactly what it is. Pure unobtanium. The 'SC' prefix is a proprietary marking for a big OEM customer, so the only way to get information is to squeeze it out of that OEM.

SC prefix =3D "special/custom" so you will not find data. What is the package? Do you have it in vivo or is it a bare chip? Pictures of the PCB?

In message , Michael A. Terrell writes

But knowing what it's on, what package etc. might be helpful. I've seen SC parts on some hard drives, other drives with the same model number and PCB revision had HC parts.. Was on old Conner drives and it was a

That chip might have been, but it's possible there was a different PC layout with subtle differences. Without actually swapping the two ICs you have no proof that they were the same. It could have been sorted for a higher speed than the standard chip's specs, as well.

SC =3D Semi Custom

Michael,

Thanks for the insight. That explains why I couldn't find anything at all. Not necessarily good, but good to know.

Thanks,

-DC

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In message , Michael A. Terrell writes

Which I did. Perfect. So although there may have been 'subtle' differences, functionally there were none.

Could well have been but the chips swapped over just fine, I did it to prove a point to a colleague who argued exactly the same things you have.

The clock oscillator was identical across the boards as well and I'm fairly certain the basic 68HC11A1FN didn't have any fancy clock multiplier or internal PLL but it's been a long time since I used one.

I built my own 68HC11 dev boards with chips salvaged from dead drives and still have a box of salvaged chips somewhere with the SC and HC markings. Found them a few months back whilst on a hunt for an old board in my shed.

Good. My point was that some might not, depending on the reason for the custom part number. Sometimes early production runs need to be selected out of each run, but all devices meet the specs in later runs.

Do you have that sc part number? Post it with the HC you replaced it with, it might help someone.

The reason I pointed out possible problems is that I had to qualify new vendor's ICs in existing designs. Some had the same part numbers, but didn't work without a redesign of our products, so they were marked as a 'Last chance' part and other sources were tried.

I had a pile of salvaged Motorola CPU & support chips on my bench when I left Microdyne. I should have asked for them, rather than leave them to be tossed in the trash. I used them to repair our pile of 'one of a kind' test fixtures.

That might be a good thing in the long run. The bean counters get hoisted on the horns of a dilemma:

a. Support the existing fixtures without the right chips, oops the engineers have to learn something. b. Replace the existing fixtures with new fixtures, the new engineers have to learn something and build something. c. Try to buy new fixtures from someone else, the bean counters get strung up and learn something and revert to a or b above.

What do you think?

They chose 'D'

d. Lay off the only person who understands the undocumented test fixtures built by former engineers, move all the work across the country to a new plant, then drop all the products that required the test fixtures as the fixtures failed.

LOL. This sounds like National Semiconductor.

No, a large defense electronics contractor.

They may have strung up a few bean counters over that one as well.

Actually such firms are usually heavily restricted by their contracts with the appropriate governmental departments. If your firm could pull such an abortion they had some smart lawyers, or smart negotiators for the original contracts.

I recall one firm I interviewed with about fifteen years ago. They had systems build around the 80186 processor, and had bought many of the chips when they were going off the market. The also bought a herd of incompletely processed chips. This was worth while because of the processing required to change the end unit (which had to do with fuel supply on helicopters).

It cost them millions in lost sales, so I hope they gutted every one of the bean counters.

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Sporadic E is the Earth's aluminum foil beanie for the 'global warming' sheep.

A few months ago I interviewed at a company (well known one that used to make space shuttles and things ;-) that bought out a company in the opposite corner of the state and moved it to their local facilities. The only person in the company who didn't quit was a guy who was already working remotely. He only had to work 100mi. in one direction rather than another. *EVERYONE* from the secretaries to engineers quit, yet they moved the company anyway. Didn't sound like a very smart "move" to me.

This move cost over 200 local jobs, with about half of the employees within five years of retirement. The company deserved what happened to it. Tooling and machines that were in perfect working order when the old plant was shut down was condemned as junk by the new employees, and all the hard learned details of each product were gone. The new people destroyed the AMP crimping machines, claiming they were crap. The company hired some former employees to train them, but they weren't willing to learn.

This contractor was buying up lots of smaller, niche market companies, as a 'Mezzanine company'. One of the founders decided to sell them his stock, and everything went to hell.

The parts I had were from scrapped boards used to build test fixtures, and ones scrapped during upgrades, or that needed too much work to repair. A lot were out of production, so I had the only spares, in house. At times, i would dig up an obsolete part from my personal shop at my house, rather than wait a month for purchasing to track down and buy a single item from a broker.