On 5/21/2010 9:57 AM, Invisible wrote:
>>> That and the subcircuit label...
>>
>> Actually, if you click on the subcircuit, you'll see some items in the
>> attributes window. One item is label. But, if you have multiple
>> instances of the same circuit and change the label for one, it changes
>> for all.
>>
>> Again, somewhat annoying.
>
> Yes, the "label" is so that if you have a dozen subcircuits, you can
> tell which type each one is. It's _not_ for labelling a specific
> instance. (E.g., if you insert a register, you can't label it with a
> register name. You can only label it with the kind of register it is.)
>

Right, but sometimes it would be nice to have a label that identifies 
the particular instance. At least, that's what I would expect when 
clicking on the item.

>>> It's trying to be helpful by detecting circuits which are unstable.
>>
>> I think it's more or less bailing out on a potential infinite loop.
>
> Hey, if it just wasn't handled, the program would crash. The fact that
> it's *noticing* the problem means that it's doing extra processing
> specifically to deal with it. But yes, it is a tad annoying. (Presumably
> the problem goes away if you use the built-in latch primitive...)
>

Well, of course the built-in latch primitive doesn't exhibit that 
problem. But with the Falstad app, the oscillation tends just to 
continue due to the way it's simulated. Logisim uses a propagation 
method where the values are carried from one component to the next, 
which can cause an infinite loop. Whereas Circuit Sim uses a timeslice 
method, where the entire circuit is calculated each tick, an oscillation 
can occur without any detriment to the program.

>>> Yeah. The whole wiring concept is just awkward. For example, Reactor
>>> (which has nothing to do with electronics but does involve wiring things
>>> together) has wires that go in a straight line from pin to pin. And when
>>> you move stuff, IT DOESN'T BREAK ALL THE WIRES OR RANDOMLY CONNECT THEM
>>> TO OTHER PINS! Sheesh, it's not rocket science...
>>
>> Actually, it can be a little tough to reroute wires when restricted to

>
> All I know is that I seem to spend more time trying to figure out how to
> move a component slightly to the side to make more space than actually,
> you know, designing my stuff! >_<
>

Yeah, Routing can be a pain when moving components. You can turn on an 
experimental feature where it allows you to sort of autoroute the wires 
in some cases when moving a component, but I've found if you move too 
far it will make bad connections. The algorithm that autoroutes needs to 
be a bit smarter, but I think it may be an instance of the halting problem.

>>> I'd prefer something less ugly to look at, personally.
>>
>> Well, sure, but function before form. I mean,
>>
>> this one was pretty, but was a pain to work with:
>> http://www.logiccircuit.org/
>
> What's up with it?
>

Not a clue... all the pretty ones aren't all that bright. ;)

>>> KLogic was easier to wire up. And it could do simulation graphs, which
>>> is extremely useful when you're trying to check, e.g., that your flip
>>> actually flops on the rising edge.
>>
>> Also, not available for Windows platform...
>
> I'd be surprised if nobody has ported it yet... but yeah, that's the
> least of the problems. A simulator that gives you THE WRONG ANSWER isn't
> very useful.
>

No, I suppose not. :)

>> http://www.falstad.com/circuit/
>
> I didn't even know that thing had logic gates...
>

It does. While it makes a great general circuit simulator, for anything 
non-trival its far from ideal for logic simulation, though.

>> The hex editor when I get finished with it will be very nice, though.
>
> No it won't. You'll never finish it. >:-)

Now I'll finish it just to prove you wrong, so ... Nyah!
-- 
~Mike

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