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Re: gEDA-user: lost newbie

Al Davis wrote: 
This is much too complex a circuit to be your first SPICE
sim. I   suggest starting much smaller. Seriously consider
verifying that resistors follow Ohm's law for your first try
(no, I am not trying to insult you: SPICE is *hard* to use).

agreed. At this point I can be considered a highly experienced user of a certain commercial cad tool and an experienced designer. So what did I do a month back? I simulated a circuit from school 15 years ago because I was learning yet another new feature in the simulator and wanted to verify that the simulator did what I thought it should do. If I were to switch to another simulator I'd do the same thing.

Most profs that I know wait until electronics, at the diode or one-transistor level. Then they use something that hides the netlist, usually the PSPICE demo. The books are written for it, and they too hide the netlist. It takes them about 3 classes to introduce it to the one transistor level, and they still can't use a netlist. Then they drop it because it is unimportant, and is considered to be a nuisance.

And the reality of it is that you will never (at least as far as I can see) escape needing to understand netlists if you make any serious use of a simulator. I still have to look at the netlists generated sometimes with the high $$ commercial tool I use. When the GUI runs amok, and evidently you can't pay enough money for this to not happen, you _have_ to be able to look at the netlist and figure out what happened.

Then later, in another course, they need to do more. They never learn that you can use the simulator to see things you can't see in the lab. Homework assignments are cut down so they fit the PSPICE demo. They still never see the netlist.

mmmmmm gnucap. mmmmm being able to do things like look at diode junction current independently from current charging capacitances.


At some point, they move to something like Cadence or Mentor, which has the multiple programs like gEDA. They can't run it at home, so they limit their exposure to it, struggle for days with it. It is as hard to use as gEDA. Even at this point, they still are not past what oregano and Spice 3f5 can do.

FWIW, I actually find basic simulations within cadence to be pretty easy, but I am pretty far removed from being a beginner. But for basic stuff it's not too hard to get up and going. I don't know why you'd bother with it in an academic environmnet unless you were planning on doing some real IC design where you had to do the layout as well. The inability to access it on your own or after you leave school is just too big a price. Thats why I quit using matlab. I was writing too much code in school that I wanted to be able to carry forward with me so I switched to scilab.

-Dan