Reply by Clifford Heath●November 16, 20162016-11-16
On 17/11/16 06:47, bitrex wrote:
> I hear the robot civilizations of the far future will spend an enormous
> amount of effort searching for the remnants of the First Compiler, the
> assembly language program which boostrapped the first higher level
> program, from which the compilers for all future programs derived.
There is only one program. All the programs that we see are just
modified versions of that first one. Oommmmmmmmm!
Reply by m II●November 16, 20162016-11-16
On 16-11-16 10:59 AM, Tim Wescott wrote:
> You can make a NAND gate in SPICE, and if you have a NAND gate you can
> synthesize all other logic. You can build a Turing complete computer out
> of logic. So, assuming you can make an infinite number of NAND gates in
> SPICE, it is Turing complete.
>
I finished assembling an infinite number of NAND gates just yesterday.
It took slightly longer than I had anticipated. Sadly, my workbench
being what it is, the assembly has gone missing. I'm not happy.
Learn from my mistake and connect your next project to the power supply
upon completion. That way, with any luck, you can follow the leads to
the terminals.
mike
--
It is hard enough to remember my opinions, without also remembering my
reasons for them!
--Friedrich Nietzsche
Reply by bitrex●November 16, 20162016-11-16
On 11/16/2016 01:43 PM, John Larkin wrote:
> On Wed, 16 Nov 2016 11:59:37 -0600, Tim Wescott <tim@seemywebsite.com>
> wrote:
>
>> On Wed, 16 Nov 2016 12:12:36 -0500, bitrex wrote:
>>
>>> On 11/15/2016 09:25 PM, John Larkin wrote:
>>>> On Tue, 15 Nov 2016 20:08:22 -0600, Tim Wescott <tim@seemywebsite.com>
>>>> wrote:
>>>>
>>>>> On Tue, 15 Nov 2016 15:25:33 -0800, John Larkin wrote:
>>>>>
>>>>>> On Tue, 15 Nov 2016 17:17:00 -0600, Tim Wescott
>>>>>> <tim@seemywebsite.com>
>>>>>> wrote:
>>>>>>
>>>>>>> On Wed, 16 Nov 2016 00:04:13 +0100, Piotr Wyderski wrote:
>>>>>>>
>>>>>>>> Hello,
>>>>>>>>
>>>>>>>> I have a resistor R5 with some current flowing through it.
>>>>>>>> It is possible to plot I(R5) by simply selecting the resistor.
>>>>>>>> But is it possible to plot dI(R5)/dt? If yes, then how?
>>>>>>>> An example circuit:
>>>>>>>
>>>>>>> Not directly, but you can make a current-dependent voltage source
>>>>>>> that has a Laplace transfer function for the gain. It'll need to be
>>>>>>> of the form H = s / (tau * s + 1), because SPICE doesn't like nekkid
>>>>>>> differentiators.
>>>>>>
>>>>>> Or just use a buffer and a C-R circuit.
>>>>>
>>>>> Killjoy.
>>>>
>>>> I like to build my own test equipment in Spice.
>>>
>>> Is Spice Turing-complete? Could you simulate a digital computer within
>>> Spice? Given enough time and processing power, could one simulate an
>>> Spice computer that could run Spice?
>>
>> You can make a NAND gate in SPICE, and if you have a NAND gate you can
>> synthesize all other logic. You can build a Turing complete computer out
>> of logic. So, assuming you can make an infinite number of NAND gates in
>> SPICE, it is Turing complete.
>
> LT Spice already has the basic logic gates and flops. They typically
> need a little timing fudging to build things like shift registers and
> state machines.
I hear the robot civilizations of the far future will spend an enormous
amount of effort searching for the remnants of the First Compiler, the
assembly language program which boostrapped the first higher level
program, from which the compilers for all future programs derived.
Reply by John Larkin●November 16, 20162016-11-16
On Wed, 16 Nov 2016 11:59:37 -0600, Tim Wescott <tim@seemywebsite.com>
wrote:
>On Wed, 16 Nov 2016 12:12:36 -0500, bitrex wrote:
>
>> On 11/15/2016 09:25 PM, John Larkin wrote:
>>> On Tue, 15 Nov 2016 20:08:22 -0600, Tim Wescott <tim@seemywebsite.com>
>>> wrote:
>>>
>>>> On Tue, 15 Nov 2016 15:25:33 -0800, John Larkin wrote:
>>>>
>>>>> On Tue, 15 Nov 2016 17:17:00 -0600, Tim Wescott
>>>>> <tim@seemywebsite.com>
>>>>> wrote:
>>>>>
>>>>>> On Wed, 16 Nov 2016 00:04:13 +0100, Piotr Wyderski wrote:
>>>>>>
>>>>>>> Hello,
>>>>>>>
>>>>>>> I have a resistor R5 with some current flowing through it.
>>>>>>> It is possible to plot I(R5) by simply selecting the resistor.
>>>>>>> But is it possible to plot dI(R5)/dt? If yes, then how?
>>>>>>> An example circuit:
>>>>>>
>>>>>> Not directly, but you can make a current-dependent voltage source
>>>>>> that has a Laplace transfer function for the gain. It'll need to be
>>>>>> of the form H = s / (tau * s + 1), because SPICE doesn't like nekkid
>>>>>> differentiators.
>>>>>
>>>>> Or just use a buffer and a C-R circuit.
>>>>
>>>> Killjoy.
>>>
>>> I like to build my own test equipment in Spice.
>>
>> Is Spice Turing-complete? Could you simulate a digital computer within
>> Spice? Given enough time and processing power, could one simulate an
>> Spice computer that could run Spice?
>
>You can make a NAND gate in SPICE, and if you have a NAND gate you can
>synthesize all other logic. You can build a Turing complete computer out
>of logic. So, assuming you can make an infinite number of NAND gates in
>SPICE, it is Turing complete.
LT Spice already has the basic logic gates and flops. They typically
need a little timing fudging to build things like shift registers and
state machines.
--
John Larkin Highland Technology, Inc
picosecond timing precision measurement
jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com
Reply by Tim Wescott●November 16, 20162016-11-16
On Wed, 16 Nov 2016 12:12:36 -0500, bitrex wrote:
> On 11/15/2016 09:25 PM, John Larkin wrote:
>> On Tue, 15 Nov 2016 20:08:22 -0600, Tim Wescott <tim@seemywebsite.com>
>> wrote:
>>
>>> On Tue, 15 Nov 2016 15:25:33 -0800, John Larkin wrote:
>>>
>>>> On Tue, 15 Nov 2016 17:17:00 -0600, Tim Wescott
>>>> <tim@seemywebsite.com>
>>>> wrote:
>>>>
>>>>> On Wed, 16 Nov 2016 00:04:13 +0100, Piotr Wyderski wrote:
>>>>>
>>>>>> Hello,
>>>>>>
>>>>>> I have a resistor R5 with some current flowing through it.
>>>>>> It is possible to plot I(R5) by simply selecting the resistor.
>>>>>> But is it possible to plot dI(R5)/dt? If yes, then how?
>>>>>> An example circuit:
>>>>>
>>>>> Not directly, but you can make a current-dependent voltage source
>>>>> that has a Laplace transfer function for the gain. It'll need to be
>>>>> of the form H = s / (tau * s + 1), because SPICE doesn't like nekkid
>>>>> differentiators.
>>>>
>>>> Or just use a buffer and a C-R circuit.
>>>
>>> Killjoy.
>>
>> I like to build my own test equipment in Spice.
>
> Is Spice Turing-complete? Could you simulate a digital computer within
> Spice? Given enough time and processing power, could one simulate an
> Spice computer that could run Spice?
You can make a NAND gate in SPICE, and if you have a NAND gate you can
synthesize all other logic. You can build a Turing complete computer out
of logic. So, assuming you can make an infinite number of NAND gates in
SPICE, it is Turing complete.
--
Tim Wescott
Control systems, embedded software and circuit design
I'm looking for work! See my website if you're interested
http://www.wescottdesign.com
Reply by bitrex●November 16, 20162016-11-16
On 11/15/2016 09:25 PM, John Larkin wrote:
> On Tue, 15 Nov 2016 20:08:22 -0600, Tim Wescott <tim@seemywebsite.com>
> wrote:
>
>> On Tue, 15 Nov 2016 15:25:33 -0800, John Larkin wrote:
>>
>>> On Tue, 15 Nov 2016 17:17:00 -0600, Tim Wescott <tim@seemywebsite.com>
>>> wrote:
>>>
>>>> On Wed, 16 Nov 2016 00:04:13 +0100, Piotr Wyderski wrote:
>>>>
>>>>> Hello,
>>>>>
>>>>> I have a resistor R5 with some current flowing through it.
>>>>> It is possible to plot I(R5) by simply selecting the resistor.
>>>>> But is it possible to plot dI(R5)/dt? If yes, then how?
>>>>> An example circuit:
>>>>
>>>> Not directly, but you can make a current-dependent voltage source that
>>>> has a Laplace transfer function for the gain. It'll need to be of the
>>>> form H = s / (tau * s + 1), because SPICE doesn't like nekkid
>>>> differentiators.
>>>
>>> Or just use a buffer and a C-R circuit.
>>
>> Killjoy.
>
> I like to build my own test equipment in Spice.
Is Spice Turing-complete? Could you simulate a digital computer within
Spice? Given enough time and processing power, could one simulate an
Spice computer that could run Spice?
Reply by Jim Thompson●November 16, 20162016-11-16
On Wed, 16 Nov 2016 00:04:13 +0100, Piotr Wyderski
<piotr.wyderski.no.spam@gmail.com> wrote:
>Hello,
>
>I have a resistor R5 with some current flowing through it.
>It is possible to plot I(R5) by simply selecting the resistor.
>But is it possible to plot dI(R5)/dt? If yes, then how?
>An example circuit:
>
>Version 4
>SHEET 1 916 680
>WIRE 256 16 144 16
>WIRE 464 16 336 16
[snip]
>SYMATTR Value U309
>TEXT 110 216 Left 2 !.tran 4
Download LTspiceTutorials.zip from the Simulation Tools & macros page
of my website, and extract.
LTspice will do the time derivative via ddt(x), but apparently doesn't
do a general d(x)/d(x-axis-variable) like PSpice.
...Jim Thompson
--
| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| STV, Queen Creek, AZ 85142 Skype: skypeanalog | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
I'm looking for work... see my website.
Reply by George Herold●November 16, 20162016-11-16
On Wednesday, November 16, 2016 at 6:36:43 AM UTC-5, circuitmaker wrote:
> George Herold wrote:
>
> > In general differentiation blows up at high frequency,
> > (where things are changing faster) and you have to
> > roll it off.
>
> I think it is a general question of doing math operations
> on the sim results, which AFAIK is not something very
> user-friendly in LTspice. Exporting the results and finishing
> processing in, say, Octave is doable, but very inconvenient.
> Another option is to co-simulate your own analog computer
> the John Larkin's way, but if the operation is more complex,
> this approach quickly runs out of steam.
>
> c.
Yeah, my mistake. Late at night and too quick a read.
George H.
Reply by o pere o●November 16, 20162016-11-16
On 16/11/16 00:04, Piotr Wyderski wrote:
> Hello,
>
> I have a resistor R5 with some current flowing through it.
> It is possible to plot I(R5) by simply selecting the resistor.
> But is it possible to plot dI(R5)/dt? If yes, then how?
Copy the current at R5 with a current-controlled current source and
apply this current to an auxiliary inductor. The voltage across the
inductor will be L*dI(R5)/dt
Pere
Reply by circuitmaker●November 16, 20162016-11-16
George Herold wrote:
> In general differentiation blows up at high frequency,
> (where things are changing faster) and you have to
> roll it off.
I think it is a general question of doing math operations
on the sim results, which AFAIK is not something very
user-friendly in LTspice. Exporting the results and finishing
processing in, say, Octave is doable, but very inconvenient.
Another option is to co-simulate your own analog computer
the John Larkin's way, but if the operation is more complex,
this approach quickly runs out of steam.
c.