Re: mystery dac

On Mon, 10 Apr 2006 18:11:07 -0700, John Larkin
<jjlarkin@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx> wrote:

On 10 Apr 2006 15:09:44 -0700, hill@xxxxxxxxxxx wrote:

John Larkin wrote:
I'm trying to reverse-engineer, or at least understand, an old hunk of
military electronics, part of an aircraft heads-up display. One part
on the schematic seems to be a 12-bit DAC with internal data latches.
The part number seems to be DAC871 or possibly DAC671; it's a bad
scan of a bad Xerox. Heck, there's a chance it's a DAC571.

It looks like a 24-pin package with D0..D11 on pins 1..12
respectively, and D0 looks to be the MSB!

That exactly the description of the Micro Networks (an ICS company)
DAC87. I don't know what to say about the "1" after the 87. Is it in
a ceramic side-brazed DIP package? Oh, I forgot, you're only looking
at a schematic, right? Would you like a copy of the data***? Done.

Winfield.


Thanks, Win, that was it. Probably DAC87I.

How many datasheets do you have archived? How do you organize them?

I have about 2000, around 800 mbytes, on my hard drive, plus a lot od
old cd's lying around in heaps. I'm planning to start an official
company archive, where we save a data*** of any part we use on any
design.

John

Back in the day of paper data sheets, we used the EEM file system.
This used a four digit number for categories, such as 1500 for
capacitors. There were additional sub folders based on the component
sub-type. They published an index whereby you could look up any
component type in an index and find the correct file number, and
provided nice category lables for the file folders.

As we morphed into the internet age, we essentially duplicated this
file system on our server. The only difference is that under each
file number we categorize components in manufacturer folders.

Our parts managemement database has links for each part to the
data*** in the database. Our electronic database now has about
11,000 datasheets using 20GB of disk space. Since this is on our
server, it is on a mirrored RAID storage system with daily tape
backups.

We emptied the file cabinets last year of the old paper data sheets in
order to make space. Now our electronic filing system looks strange,
but we won't change it because this would break all the data***
links in our parts database. If you go to www.eem.com and push down
to a component category you can still see the four digit code in the
web page address (such as Code=1500 for capacitors), so even they
still use the code for historical reasons.


================================

Greg Neff
VP Engineering
*Microsym* Computers Inc.
greg@xxxxxxxxxxxxxxxxxxxxxxxxxx
.

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