LOGO-L> Re: MMLogic

[George Mills <mills@softronix.com>]

I hope Logo folks don't mind my posting this response because this
has common requests and many MSWLogo users use MMLogic. GSN folks had
said they would set up a mailing list but they never came through :-(
There is also some talk about hooking it into MSWLogo so it's not
completetly a non Logo response :-).

Does anyone out there have the authority to create an "alt" news group.
I have tried the usual methods but the you need someone that manages
a news server I think to push the request through.

Das Menon wrote:
> 
> Hello Geroge,
> 
> Now that I am gaining a little more experience in using MMLogic, I find that
> if it had the following features, it will be useful. Perhaps you an consider
> these in forthcoming versions?
> 
> 1.      Delay element:
> 
>         I find that I need to sometimes slow things down so that bit changes
> in the circuit can
>         be visually followed as an aid. So I need to introduce some kind of
> a delay in the signal. I
>         tried the method of using a counter and using the carry bit to drive
> the next circuit. But I found
>         that to really slow down I need to add a bunch of 8 segment displays
> also to the output of
>         the counter, which makes me suspect that speed reduction is achived
> only because the
>          computer now has more things to update.
> 
>         Does MMlogic have a delay type element? The other (probably a
> better) way to slow
>         things down is to specify as part of the property of the
> 'osicllator' a duty cycle. Curently
>         you can select how many higs and lows, but not how many total
> higs/lows per second.
>         It will be great if I can click on the oscillator and say that I
> want to it to provide an output
>         say ones every second.

A delay element exists. Use an Inverter and modify it to remove the
bubble
(change it to a buffer). String a few along for added delay. I have
thought
of adding a delay device where you can just set the delay rather than
string them along, but that would just make it easier but same
functionality.
Many examples use a buffe in this fashion.

I just reread your question. You can slow things down by using a Timer
Device
instead of an oscillator and set the duty cycle to a real wall clock
time
value (1/10th of second, 1/100th second etc.) Many examples use this
method
for the reason you explained.

> 
> 2.      Device Orientation:
> 
>         As it is now all the elements are oriented to receive inputs from
> the left and send the output
>         to the right. Sometime I need to create a feedback path where the
> inputs are coming from
>         the right and the output is going to the left. So if we can have a
> command like 'rotate <angle>'
>         this can be resolved.

It probably will be a while before you see this. You can use "Node"
devices
to route the feedback wires.

> 
> 3.      Library elements:
> 
>         Here I am talking more like the subroutine concept. Where I can use
> gates to built a module,
>         then use that module in a bigger circuit etc. To do this I should be
> able to save a circuit as
>         a library element or module, which has well defined input and output
> pins/points. I guess
>         this is more involved to implement!
> 

Library elements are different from "Macro's". I do plan for some sort
of Macro. Someone mentioned a simple way to do a macro would be to
dedicate
a "page" to that subcircuit, and mark the page as a macro that can be
called up from another page.

A library element would be something so the user could add a native
device
to the tool bar etc. and suppy a bitmap and behavior code. This is
a lot harder. But I may offer hooks to OLE Servers so you could hook in
Excel or MSWLogo.

>
> 4.      Drill down:
> 
>         Related to item3, a more advanced capability will be to drill down
> on a circuit consisting
>         of modules to reveal the gates or even other sub-modules inside the
> module, till one gets
>         down to the basic gates implementing the module. Something like the
> 'zoom in' capability
>         that Geographic Information Systems have ie. the ability to click on
> a state map to reveal the
>         counties, click on the counties to reveal the cities, click on the
> cities to reveal the roads, click
>         on the roads to reveal the blocks, click on the blocks to reveal the
> houses, click on the ........

I know what your talking about but the "page" scheme I explained above
would be easier and more timely to implement.

> 
> I have not yet fully explored the whole MMLogic, since I tend to build as I
> explore (or explore as I build!), so probably some of these things are
> already in. If so, pls guide me to it.
> 
> Thanks & Regard...Das
> 
> ps.     There can be some sort of a 'programming language' which can be
> used to model the
>           modules, if the graphical approach is too difficult to implement.
> Of course the graphical
>         approach is superior, since it is closer to the designer than the
> programming language
>         approach, which is probably alright for a programmer ( I do recall
> righting a 'program'
>         as part of my graduate studies at USC where I had to design a VLSI
> chip where the actual
>         internal logic was completely described using an extended Algol
> program!)
> 
>         A final comment is perhaps as things go forward, you can have a
> feature in the simulate
>         command that will analyse timing erros. (Perhaps it does that
> already?) A logic gate level
>         SPICE type program!

I'm working on a Logic analyzer now. It probably will not have
have "triggers on the first release". That is, it will capture the
whole simulation.

Spice is really an analog analysis of circuit.

I'm also adding a Tape Drive Device so you can build a slick
Turing Machine among many other things.

-- 
===============================================================
George Mills
email: mills@softronix.com
http://www.softronix.com
The www page contains some very powerful educational software.
Our single most important investment is our kids.


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