gEDA: Type numbers for transistors

[Wojciech Kazubski <wk-at-NOSPAMire_dot_pw_dot_edu_dot_pl>]

Hi All!

Few days ago Antonio asked for making device= attribute editable for some 
microcontrollers.
The same, or even greater, problem exists for discrete devices, especially 
for transistors. There are thousands of devices which share the same symbol, 
but sometimes they have different pining. This is especially true for TO92 
package that has 5 different pinning (of 6 possible) - compare BC548, BF240, 
2SC1815, 2N3904 for example. 
PCB generally use pin numbers but there is a file (transistor.m4) that seems 
to contain pinning for some, but very few, transistors. I have problem with 
making this working :-(.  The board created by gnetlist -g PCBboard has pins 
"1" "2" and "3" while the netlist created by gnetlist -g PCB has pinnames E, 
B and C.

There are three solutions:
1) Create a special symbol for each device (or even three, based on 
npn-1.sym, npn-2.sym and npn-3.sym). This will take quite much disk space (at 
least  one block 1-4kB for each symbol) and may cause problems with 
mantaining the symbols.
2) Make gnetlist use pining definitions from PCB and add more entries there 
(modify PCB`s files?).
3) Make symbols like npn-ebc-1.sym, npn-bec-1.sym with pinnumbers instead of 
E, B and C. The user must then know what symbol to use (external database?) 
and the device= attribute must be editable. 

Which is the best?

Now the device= contains something like NPN_TRANSISTOR and must be overriden 
by a new attribute like device=BC237

W. Kazubski