[BBF Standards] Sequences and Formats and Devices, oh my! [Re: data exchange issue 1: Abstraction]

[Jake Beal]

> (1) Associate the ID numbers with the precise sequences
> * pro: ID's of classic biobricks keep their identity
> * con: same function registered under multiple ID's for repackagings in 
>   different formats
> * con: forces folks who've repackaged existing bricks in non-classic 
>   formats to reidentify their samples
>
>(2) Biobrick ID's associated with function
> * pro: functional classifications of biobricks remain the same
> * con: will lead to mixups between people because formats might not match

A nice mid-point between these two options is found in the TTL
Databook approach to classifying digital circuits packages.  The IDs
of TTL devices encode their function, format, tolerance, and package
in different portions of the ID.  This entire functional family is
listed in a single datasheet, with notes about values that vary by
family.  (It may be noteworthy that the opacity of chip packaging means
that, like BioBricks, it extremely hard to determine the function,
format, or other characteristics of a chip except by its ID).

For example, flipping open my TTL databook at random, I find the SN-86
family: "QUADRUPLE 2-INPUT EXCLUSIVE-OR GATES."  This 5 page datasheet
describes a family of 6 devices with different IDs, available in 13
ID/package combinations.  Pages 1 and 2 give all of the functional
information for the devices, as well as all of the critical
information about how the family varies.  The remaining three pages
give differences in interface and environmental characteristics.

The six devices are the SN5486, SN54LS86A, SN54S86, SN7486, SN74LS86A,
and SN74S86.  These numbers decompose into four fields:
- The SN prefix is assigned to all the TTL devices in the book
- 54 means milspec tolerances, 74 means civilian tolerances
- the middle letters (LS, S, or nothing) indicate the implementation
  technology: Standard TTL, Schottky, or Low-Power Schottky
- 86 indicates the functional family (quad 2-input xor gates)
- the A on the end of the 'LS86s indicates it is the first revised verions.
  Maybe something was wrong with the original 'LS86 design?

Finally, these are available in a few different packages:
- SN5486: J or W package
- SN54LS86A, SN54S86: J, W, or FK package
- SN7486: N package
- SN74LS86A, SN74S86: D or N package


A similar decomposable ID scheme for BioBricks would satisfy the
needs for unifying function while distinguishing formatting,
versions, and classic biobricks.

Thanks,
-Jake