Re: gEDA-user: 74xx symbols

[John Sheahan <jrsheahan@optushome.com.au>]

On Tue, Jul 30, 2002 at 11:18:05PM -0700, Jim Battle wrote:
> 
> But these are just text items -- they have no use to a netlister; they are 
> there just as an aid to human comprehension.  Edit a symbol (say, 
> 7474-1.sym); select Q, type "ee" to edit the thing, and it is just 
> text.  You could replace it with the gettysburg address if you made the 
> point size small enough.
> 
> I haven't tried all of the netlisters, but I tried ged and verilog and both 
> of them just used the pin numbers as the pin label.  Perhaps a clever 
> netlister could guess the nearest text and use that instead, but it seems 
> prone to failure.  My understanding is that whenever the new library comes 
> out, there will be an explicit "label=xxxx" property attached to every pin, 
> allowing for more rational netlists for verilog, among others.

I'm no geda expert. I am used to pins having a name and optionally  a
number.  Numbers seem useful really only for pcb work. 
Names are for logical binding, and usually appear (ie visible) on 
schematics.      Text can be optionally added too. 

do anything needed in text for extra clarity, but the pin names 
should be unique and meaningful.  

de Morgan equivilants are a great thing.  too few people feel the need
unfortunately.  Used properly a schematic is much easier to read with them.
john


> 
> -----
> Jim Battle == frustum@pacbell.net