Comments received in English

The masterpiece of TI-89 programming.

Alex Astashyn
EE+CoE+CoS major, Polytechnic University in Brooklyn, New York, USA (Born in Russia)

Symbulator is and always will be the best program for TI-89/92/V200.

Charles Ware
EE major, Columbus, Ohio, USA

Roberto, your program Symbulator is by itself a reason to buy the calc. It's a masterpiece of programming.

Pepe Iborra
Telecommunications, Spain

The program is really a masterpiece. It gives you everything you need, very accurate, very fast. It's really what every Electrical Engineer dreams of. It's so easy to use and it does everything! DC, AC, Trasient analysis, Thévenin, Bode plots... everything! I'm really amazed. Keep up the good work...

Nikolaos Trichakis
EE major, Aristoteles University of Thessaloniki, Greece

Brillant work by Mr. Pérez-Franco! Check it out!

Arne Harstad
EE major, Norges tekniske-naturvitenskapelige Universitet, Stavanger, Norway

Congratulations for your program: it's simply fantastic. Symbulator is worth the cost of a TI-89!

Pier Giorgio Raponi
Engineering student, Pisa, Italy

I wish I had it while going through school.

Joe Riel
BSEE & Creator of Syrup (a symbolic circuit simulator for Maple V), University of California, Irvine CA, USA

Symbulator is a wonderful tool.

Reinhard Willinski
EE major, Germany

It runs beautifully in TI-89.

Harold Martínez
CoE major, City College, New York, USA

I find Symbulator to be a phenomenal program. You did a great job. The more I use it, the more I want to use it.

EE/CoE student, San Diego State University, USA

Totally awesome! Thanks a million.

Chris Spencer
EE major, University of Florida

You've made a excellent program. Symbulator is really the best circuit simulator ever made for a calculator.

Rui Sebastiao
EE major, University of Coimbra, Portugal

Your program is absolutely great, and I use it all the time, not without enjoyment. (...) This is a great program, Roberto, and I hope you continue developing it.

Carmel Nachmany
EE major, Ben-Gurion University of the Negev, Israel

Symbulator is a great tool to check answers.

Brad Norman
EE junior, Montana State University, Bozeman, US

Congratulations for your software Symbulator. It's great!

Eduardo Silveira
EE major, Brazil

Thanks for an exquisite, free program!

Chandler Sorenson
Computer Engineering, University of Arizona, Tucson, US

Symbulator is probably the most useful program ever made for a TI calculator. I am an electronics student and even paid for the EE*Pro software, yet I find myself using Symbulator more because it is much better at what it does.

Josh Cunningham
Electronics major

Symbulator, by far, has been the best tool for EE I have come across yet. (...) It is truly an impressive piece of work. You should be proud. It certainly is helping me to focus on my studying of EE instead of trying to remember all the math. Again, good job!!

Jim Wachtel
EE, Process Control & Electrical Co., St. Louis, Missouri, USA

Your programs are the best thing I have ever seen on the TI website. I can tell that you are making a lot of engineering college students happy.

Ade George
EE major, Morgan State University, USA

I love this program! Trying to learn how to use it has increased my knowledge of actual circuit analysis, which helps me out in the long run. Your software is great. I'm taking my first ELEN class and this software not only confirms my work, but helps me understand the circtuits as well.

Josh Earley
Computer Engineering major, Texas A&M University, USA

I wanted to tell you that I've been trying out a few programs on my calculator recently and this is by far the most impressive. I am studying to be an Electrical Engineer and while I enjoy solving problems by hand, this really impressed me as a way to check my work! I stayed up late last night just seeing if I could solve problems from my old Circuits text book.


I will, one day in the near future, buy a TI-89 just to use your Symbulator.

Ron Ross

This program is the premiere circuit solver for calculators. Yes, there are others, but none are better. This program is similar to SPICE or PSpice in the way it is used, and it is even easier when it comes to dependant sources and biport simulations. Once a circuit is solved, it has ALL the information the user would want: node voltages, element currents, element power usage, voltage drops across elements. It solves symbolically, unlike almost any other circuit simulator (even PC based). This program is, hands down, the best program for circuit analysis that I have seen. Big circuits can be slow to solve, and can run the calculator out of memory. Work-arounds are out there, including tools for breaking the circuit into groups of Thévenin or biport equivalents. I could not possibly praise this program well enough. It's hard to believe that Mr. Perez-Franco is letting the world use his fantastic program free of charge. Excellent job!

Jay Myers
EE major, University of Texas at Arlington, Texas, USA

I have been using your wonderful program for about four months now. The freedom it affords is amazing. (...) I use Symbulator extensively for analysis and design in EE and find it easier to use (and really a better learning tool because you must understand what you are doing) than PSpice. I am truely impressed with the efficiency of the program and the simple fact that I have had no problems with the program itself.

Douglas Fisher
BioMedical Eng, Math Wright State University, Ohio, USA

I think your program is absolutely great. (...) Your Symbulator is the neatest thing to have around. (...) Good job, Roberto. (...) What a great program by such a gentleman.

Tim Hutcheson
BS in Comp Sci, Institute for Human and Machine Cognition, Florida, USA

Let me congratulate you on Symbulator. Amazing job! I have EE200 and EEPro, but your app seems to far surpass the capabilities of these two apps.

Ralph McCarthy
EE major, Minneapolis, Minnesota, USA

I think your program is one of the best programs out there in the community, and in my personal Top 10 chart, it's in the top. It was the reason I bought the ti-89 for in the first place. I have distributed the Symbulator to everybody in my class and they've been enjoying it a lot when solving EE problems.

Melnic Atrav
EE major

Hey, hats off to the programmer of this one, and for the generousity to share it so freely. I guess it's too bad I bought EE*Pro for $50 less than a week ago, huh?

Brandon Newsom
High school student, Newport News, Virginia, USA

A million thanks for your program. You don't know how fine I feel every time I solve a circuit with paper and pencil, and I get the same answers I got with Symbulator. It is much easier to learn this way. Truly, I believe you deserve a mention in circuits books.

Gabriel Florit
EE major, Dordt College, Sioux Center, Iowa, USA

Thank you for your brilliant program. (...) I have used your program quite a bit throughout my studies. (...) I have to commend you on such a comprehensive and impressive program. In my mind, it is the most important program to have on a calculator for those taking EE courses. (...) Thanks for your time, and for your Symbulator, Roberto.

Albert Meng
System Science Mathematics major, Washington University, St. Louis, USA

It is a great way to check your answers in homework and on a test. Try it out for yourself, that is the only way you will figure out what Symbulator is capable of. I am still amazed about how well Roberto's program works...

Al Charpentier
EE major, Pennsylvania State University, Pennsylvania, USA

We all know about SPICE and what a lifesaver it is in our design projects, but the learning curve has always been a steep one. In my quest for the best EE applications for design and analysis, I came across Roberto Perez-Franco's Symbolic Circuit Simulator (Symbulator) for the TI-89. I have been using Symbulator for almost a year now, and believe me, it is a must for every electrical engineering student.

Perhaps the most startling aspect of Symbulator is it's fully symbolic implementation. Answers are left in terms of variables instead of being converted into numeric approximations. This allows for easier analysis, interpretation, and plotting. If you're taking Dr. Gedney's Circuits II course, Symbulator will save you every time. Dr. Gedney is infamous for assigning problems which do not have solutions in the textbook. With Symbulator, the solution is only seconds away, and a better understanding can be obtained by reverse-engineering the problem so you know you understand the correct solution.

Since the interface to Symbulator is similar to SPICE, once you know one, you can use both. For EE 211 and EE 221, Symbulator actually works better than SPICE because you get the results symbolically. Once you use Symbulator you'll see what everybody has been talking about.

If you're not using Symbulator, you're working too hard.

Chris Riegel
EE+CoE major & President of the IEEE student chapter in his U., University of Kentucky, Kentucky, USA

I am really satisfied with the program. (...) I have greatly enjoyed using your program and have convinced most of my classmates to use it also. (...) I am on my third year in EE and have used Symbulator since day one. I am still using it on a regular basis.

Nevin McChesney
EE major, University of Kansas, Member of the US Navy, USA

I would like to thank you for creating such a great tool for EE analysis. I especially appreciate that you released it for free.

Jeff Bach
EE & Music major, University of New Mexico, New Mexico, USA

I'd like to congratulate you on the success of Symbulator for the TI-89... it seems to be used and appreciated by many students.

Paul King
Texas Instruments, Texas, USA

Perez-Franco's Symbulator and Frederiksen's DiffEq programs are two musts for any serious TI-89 user!

Daniele Martini
EE major & author of S2S plug-in for Symbulator, Florence, Italy

The TI-89 opens up all kinds of opportunities for useful programs, the Symbulator suite being a great example.

Michael Rans
E+CSc major, Oxford University, London, UK

When I start my next circuits course and my first Controls course in the fall, I know Symbulator will be my best friend once again, especially with all of the improvements you have made.

Charles Ware
EE major, Ohio State University, Columbus, Ohio, USA

Just want to say that I admire your work. (...) I enjoy developing programs for my TI89 that help solving my day by day problems. That's why I admire your work.

Sergio Coelho
Engenharia Electrotecnica, Faculdade de Engenharia da Universidade do Porto, Portugal

Me and all of my friends at the University of Texas in Arlington think the circuit simulator is great. Thank you for all of your hard work on this program.

Jeffery Allen
EE major, University of Texas at Arlington, Texas, USA

I'm using Symbulator for only two weeks now and I can say that I am in a way addicted to your program. It is really the best software you can get for a calculator on the field of Electrical Engineering. When I show it to my colleagues at the faculty, I know that it will spread in Slovenia too. (...) Thanks again on this wonderful program.

Matic Hibernik
EE major, University of Ljubljanja, Slovenia

Congratulations for Symbulator program. It's really good!

Bernardo Merino Bermejo
EE major, Escuela Universitaria de Ingenieria Tecnica, Madrid, Spain

I really appreciate this program and I'm sure many students will as well. I hope that now all other programmers would try to create useful science programs.

Vic Fischer
Physics+CoE+EE major, Universite Jean Monnet, France

I just loaded symbulator onto my calc last night and I am liking it a lot.

Samuel Nyall Stearley

Your programs are great and useful for all students with a good calculator.

Michael Preuhs
EE major, Universität

Gesamthochschule Siegen, Germany

Thanks for coming out with such a great program.

Abhishek Shrestha
CoE Sophomore, Western Michigan University, USA

You can be really proud of Symbulator!

Kamil Malinksi
EE major, Technical University, Vienna, Austria

Thank you very much for all your hard work on Symbulator

nice job!

Doug Burkett
EE major, Eaton, Ohio, USA

Thanks for carrying me through more than two years of EE studies.

Thomas Schallhofer
Northest University of Applied Sciences, Flensburg,Germany

Thank's for doing this program!

Thomas Knoblauch
EE major, ETH, Zürich, Switzerland

Wow! Now I can do Bode Plots!!

Damion Hadcroft
ME major, Adelaide University, Australia

I'm sure this program will prove to be quite an asset.

Andrew Hockman
EE+CoE major, Missouri, USA

It is really simple. At the same time, it's a very useful, great program.

Andrej Bencúr
EE major, Technical University of Ostrava, Czech Republic

I love the software, it helps me out in the lab quite a bit.

EE major, University of Dayton, Ohio, USA

Thank you so much for letting me get this program. It has been wonderful and I appreciate all of Roberto Perez-Franco's hard work.

Jared Whitaker
EE major, UAA

I want to thank you and congratulate you as well for such a nice and useful program.

Dan Safoory
EE major

Thanks for your work. Symbulator is fantastic! (...) God has really blessed you with quite a talent for solving difficult problems. (...) I am not going to take another exam without it...

Jake Adams
ME + EE student

I love your program and I greatly appreciate all the hours and hard work you have invested. (...) I must give you partial credit for placing 2nd in my circuits class and getting a perfect score on my final exam. My advisor is no longer telling me I may want to reconsider my choice of major from electrical engineering to something more suited to my advanced age of 41.

EE major

I must say that this program looks extremely tight and well tuned. You should be hugely commended for you abilities! Great job and keep up the excellent work!

EE major

These have been great learning tools and helped reemphazise what school teaches. I have to use these tools to help me better understand rather than just mindlessly answering the questions. Thanks to this calculator, your programs and lots of hard work and studying, I actually survived my "Advanced Circuit Analysis" class, with an "A" to boot. It was a class from hell!

CoE+EE major

Roberto, you are doing a good job for TI and EE students that use TI89's and 92+'s. Keep up the good work.


on Symbulator Q

Roberto, thank you for your diligence and hard work in creating and perfecting a GOOD circuit simulator. (Not to mention FREE). The use of Symbulator has improved my learning of electrical circuits.

Nevin McChesney, on Symbulator Q
EE major, University of Kansas, Member of the US Navy, USA

Thanks, again. This is an excellent program and I am very interested in seeing the book you are writing for Symbulator Q.

Eric Wierwille, on Symbulator Q

I want to thank Roberto Perez-Franco for writing such a wonderful program

the Symbulator. Spending so much development time on the home page and software, and not charging a nickel for it, makes you a real hero. That kind of thing brings a tear to my eye! Thank you!

Bez, on Symbulator Q

Thanks for the program. It is a true gem, and a free one at that...a true rarity!

Dorian, on Symbulator Q

I must say, Rob, that once again you've outdone yourself. I hope that this isn't the last time, and look forward to more genial programs from you. Thanks for letting us enjoy the Symbulator for free. It's not often that great programs come free. You, my friend, are an example to follow.

Anonimous poster @ TI DG, on Symbulator Q

And the Oscar for Best Program of the Year for a TI calcs goes to... (drums) Symbulator Q, by Roberto Perez Franco. Huray! Huray!

Anonimous poster @ TI DG, on Symbulator Q

on Symbulator 4 (Impala)

This program is one of the major TI programming accomplishments, and in fact one the most significant programs for any calculator. (...) Until I started the (Impala) testing, I did not realize just how powerful Symbulator really is. (...) Symbulator makes it possible to solve every homework and test problem, without knowing much more than how to enter the circuit in the matrix form! (...) I have been both playing with calculators and using them professionally for over twenty years. I am quite aware of their capabilities. And I think that Symbulator is the most amazing end-user calculator program that has ever been accomplished. I am grateful to you for having done this work, and for having improved Symbulator so enthusiastically. You know that Symbulator is good enough to be a for-pay program, yet you gave it to us for free. That means a lot to me.

Doug Burkett, on Symbulator 4 (Impala)
EE major, Eaton, Ohio, USA

I'd like to thank Roberto for his effort in releasing Symbulator 4 (Impala). It's really an incredible program.

Farooq Ahmed Weshah, on Symbulator 4 (Impala)
EE major, Yarmouk University, Jordan-Salt, Jordan

I was going to sell my TI-89 because I didn't see any use for it. But this new program by Roberto made me want to try this program out. Congratulations for your work!

Marcelo, on Symbulator 4 (Impala)
EE senior, Canada (born in Chile)

Roberto, I've been enjoying your program for over a year and use it regularly. It has made my EE studies much easier over the years. (...) Thanks again for a superb program, which is the reason for which I choosed TI-89.

Gordon, on Symbulator 4 (Impala)

Another triumph in BASIC programing for 68K calculators. Awesome! I can't describe it any better.

Captain Ginyu, on Symbulator 4 (Impala)

On the IEEE Award in 2000

Congratulations on receiving the IEEE award

I believe it is very much deserved. It makes me smile to see you rewarded for your hard work and dedication to Symbulator and the TI community.

Paul King, on the IEEE Award
Texas Instruments, Texas, USA

Many, many congratulations, Roberto! Passion and intelligence will *always* beat greed and narrow vision.

Doug Burkett, on the IEEE Award
EE major, Eaton, Ohio, USA

Congratulations, Roberto. Symbulator is a masterpiece worthy of the best programs out there, free or otherwise. And the fact that it is free speaks volumes about its creator. Peace be with you always.

Jake Adams, on the IEEE Award
ME + EE student

Congratulations, Roberto!!!

Dave Conklin, on the IEEE Award
Professional TI-89 programmer

Ha! Some wise man finally discovered what so many 'meere students' have known for some time. It's so good to see some recognition for you. You deserve it.

Jay Myers, on the IEEE Award
EE major, University of Texas at Arlington, Texas, USA

On Symbulator 3 (Expert)

Once again you did a great job and I'm sure I'm not the only one who is sending you a "Thank you very much, Roberto. Our EE-life is a lot easier with your Symbulator :-)".

Kamil Malinski, on Symbulator 3 (Expert)
EE major, Technical University, Vienna, Austria

Once again, good work! I thought Symbulator was pretty much a finished and polished product and now you pull new tricks out of your sleeve! (...) Symbulator has been a very valuable tool for me. By the way, I recently passed my Professional Engineering exam. Symbulator allowed me to check some of my answers. A pretty hefty dual op-amp circuit was one I checked...

Jim Wachtel, on Symbulator 3 (Expert)
EE, Process Control & Electrical Co., St. Louis, Missouri, USA