On Mon, 2009-01-12 at 18:53 -0800, Joerg wrote: > Peter Clifton wrote: > > Actually, your idea has got me thinking more about how we handle > > attributes on slotted parts, and the possibility that they could in some > > way be treated as an aggregate component for the purposes of attributes > > other than "slot=". > > > > Not 100% sure if I understand correctly but yes, treating all slots as > one component would be feasible. Even if you don't use all you must > usually place all slots anyhow and, for example, connect inputs to GND. > Exception being transistor arrays but even they should also be grounded > and be on the schematic so folks can see what's available for cut/jumper > style rework purposes.
Sorry for typing before thinking that through fully. Treating all slots as one component (for adding attributes) isn't actually possible with gEDA's architecture. Attributes can only be added to symbols. I can imagine the GUI glossing over that fact, and perhaps offering to help keep attributes in sync when renaming a single slot, it would be difficult (perhaps impossible) to cater for the case where you have some slots on one schematic page, and others elsewhere. > That would be a serious one. I can't recall a single company I dealt > with not using A, B, and so on (upper case). Most CAD programs > auto-assign those when you place until you run out of slots. So if you > place eight slots of a six-slot 74HC14 it bumps the refdes number for > the last two you place. They don't all do it perfectly. OrCad usually > does but I've had Eagle "forget" when I began placing some more slots > later. gschem just places all as first slots with U? right now. Tricky to figure out how to do this flexibly. gEDA's flexibility means special casing behaviours like this is hard (and often undesired). Some kind of script or plugin hook might be a possible way to do this, but again.. I'm just thinking "aloud". (I'm not suggesting users would have to write these scripts, more that they shouldn't form part of gschem's hard-coded behaviour.) As an example I wrote for someone (and I ended up using it myself), I have a script hook here which renames any component I copy back to "U?" (removes the numbering), so that I don't end up accidentally naming two components the same due to a copy-paste in my schematics. Joerg: I think I have some understanding now of the kind of visual appearance of schematics you're thinking of, but I'm curious to see (if you have any examples you could share - perhaps by private email), just what the kind of schematic you're talking about looks like. (Either slotted logic gates, or slotted op-amps). I'd like to put the discussion in context by seeing how a real schematic looks using the styles we discussed, rather than just my mental pictures so far, which just cover a symbol and its visible pins. -- Peter Clifton Electrical Engineering Division, Engineering Department, University of Cambridge, 9, JJ Thomson Avenue, Cambridge CB3 0FA Tel: +44 (0)7729 980173 - (No signal in the lab!) _______________________________________________ geda-user mailing list [email protected] http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
