Strange source for SSM2040 ICs?

[Irish]

On Thu, 07 Jan 1999, Gavin Muir typed:
>Hi all,

>	Apparently Thomas Organs used to do some contract work for Moog or
>something, and somehow the SSM chips eventually got used in some of their
>products. What I got was a clearly marked SSM 2020, but also an oddly
>marked IC with a Thomas parts number on it - 5099. I phoned and asked about
>this, and apparently this is supposed to be a 2040, only it has been
>screened with the Thomas parts number instead of the usual SSM2040. I don't
>really have a circuit to test these in (I'm not putting this in a
>synthesizer to test it thank you!),  so I was just wondering whether or not
>anyone else had found this site or tested one of these chips? Is it fairly
>normal for such chips to be re-screened by a manufacturer? 

Yes. I've seen a lot of ways that manufacturers will attempt to
disguise key parts (usually ICs) in a product. Rescreening is being nice - at
least you might have a chance at cross-reference. Other not so nice ways
include removing all ID marks and epoxy encapsulation. 

It's also fairly common practice for one IC to have several ID numbers,
depending on chip maker (usually a prefix/suffix change). They all work
identically. In fact,  the only numbering 'standard' for IC's is there *is* no
standard! It's not like caps or resistors. A chip maker can call it anything
they want. 

I'm certain the part you have (if cross-refed correctly) is a drop in
replacement. 

Irish