I made a MIPS simulator

AKA MIPS – A Java Based MIPS simulator. Browse the code on GitHub.

Long story short, my Data Structures teacher gave us this project where we hasd to use our knowledge of data structures to make something useful. She said we could do it in groups so naturally I found myself in a team of 3.

She told us about the project near the start of the semester and a week before it was due we were still trying to decide what we were gonna make. She said that we would have to present our project and pitch it and convince the audience that it’s a useful piece of shit. The problem with us was that any idea we came up with was either far too advanced and therefore not worth the time and effort or far too simple for our ego to allow us to go about presenting it as our grand project.

I thought maybe we could make like a virtual machine of the Altair or any other primitive computer and that led us to the idea of making a MIPS simulator. We opened the instruction set in a browser tab immediately and were relieved to find that it was sufficiently small and therefore we decided that this was what we wanted to do.

Within 24 hours I had written a buggy but functional parser that could read assembly files coupled with a machine object using a couple of integer arrays for simulating the RAM and registers. Downloading and running some assembly code for MIPS on my parser helped me fix some bugs and typos that had crept in.

Because the teacher had insisted that the project be a graphical program, one of our team members was tasked with creating a GUI for this and so he made a JavaFX project that ended up looking very similar to the MARS simulator for MIPS. No it wasn’t at all a coincidence because he had used MARS before.

After coupling my code with the GUI, I would say we ended up with a pretty decent program. It has a few limitations, e.g. lack of floating-point support. I learned from Steve Wozniak that it’s okay to leave that out when you’re writing your own language processor. On a serious note though, I didn’t initially plan on leaving it out but I learned after it was a bit too late that MIPS had a whole set of 64 bit registers for handling floating-points and I didn’t feel like making any changes to the otherwise working parser. Other than that, there’s no support for unsigned arithmetic. The whole program is Java based and Java doesn’t have unsigned types so neither does the simulator.

The code for the program is available on github. Feel free to check it out, give your feedback and even suggest improvements. It’s not on my teammates account because he created an pushed the code for the GUI on a separate repo and then merged the parser code directly into it.

 

On “Looking Backward: 2000 to 1887” by Edward Bellamy

A couple of weeks ago, I posted about “The Sleeper Awakes.” At some point in that book, Graham (the protagonist) compares his situation to that described by Bellamy; and earlier in the book, when he is sound asleep and has only been asleep for a few decades at most, we see his friends talking about the same thing. Curious as I was upon reading that name I chose to google it. (I don’t quite remember exactly what I googled but it was probably something like “Bellamy Socialist Utopia Sleeper.”) I found out that there was a book by an Edward Bellamy called “Looking Backward: 2000 to 1887” in which a man sleeps for somewhere slightly above a century and, you guessed it, wakes up in a world vastly different from the one he slept in. I downloaded that book right away and made a mental note to read it after finishing “The Sleeper Awakes.”

A few hours ago, I finished reading “Looking Backward” and I thought I might as well write about it and throw in a few words about the similarities and differences between the two books. There are SPOILERS AHEAD so proceed at your own risk.  … 

 

Entropy of life

I know it’s kind of a weird title. I will promptly explain it. Have you ever been in one of those situations where you went ahead and did something without thinking twice only to later regret doing it and spend the next few days brooding over different ways to deal with all possible undesirable consequences of that course of action?

We often see situations like these in movies. I considered adding examples here from Harry Potter or The Flash or Infinity War but then I decided against it because I didn’t want to post any potential spoilers and because not everyone would be familiar with those scenes. Instead let me use a very general example: Something goes wrong and the protagonist(s) considers possible courses of action to take. In short, they form a plan that sounds completely nuts but they decide to do it anyway because it’s “the only way.” And all that while you’re just sitting there hoping that they’d see things your way because ot you there’s clearly another and better way but they can’t seem to think of it. Anyways, they go ahead and execute their plan only to screw up further and get themselves into a situation much worse than before and then the cycle starts again (or maybe not.)

Now that I am done typing that stupid example, I realize that it’s too general to be of any use. So let me use the example of time travel. Let’s say you have a regret. Years pass and you cannot get over it. Say you gain access to a time machine. You go back in time to fix it only to realize that you created a new world that’s equally undesirable. You try to figure out the point in time where this new world of yours went haywire and try to fix that. Again you screw shit up. Eventually you realized that you’ve messed it up to the point where it cannot be fixed. (There are actually movies about exactly this.)

Have you ever met someone and gotten to know them really well only to end up wishing you’d never met them in the first place and thinking about how your life would have been so much better if you hadn’t? Or maybe you’ve at some point said something that you immediately wanted to take back and so you keep on thinking about different ways to explain yourself should someone bring it up again and you can’t help fearing that someone would hold it against you. But anything you say to cover it up could only make matters worse.

In short, what I mean to say is that things always get worse with time. The more the time passes the greater the number of things in your life that went wrong, the more secrets you have and the more people there are that know your secrets, the greater the number of people in your life that you watch out for e.t.c. and every lame attempt to fix any of it only creates more problems. Life only gets messier and messier and there’s no way to clean up that mess.

 

 

On “The Sleeper Awakes” – H.G. Wells

I don’t exactly remember how I discovered this book. But at least a couple of months ago, I came across the name, looked up the synopsis and downloaded it with the intention of reading it on the first chance. Less than a month ago, on a particular midnight, I was unable to sleep and having little to no desire to take up something educational, I decided to go through my collection of fiction. The H.G. Wells folder caught my eye and I opened it to reveal this book along with a couple of others. Remembering suddenly what it was about, I decided to start reading it.

Fun Fact: The first chapter was called “INSOMNIA.” Also adding that although I mean to not talk in detail about any events in the book, depending on your perspective, there may or may not be spoilers ahead so proceed with caution. … 

 

Explaining Savitar to a noob be like

Me: Hey, Tom Felton made an appearance in the Flash.

They: Who’s that again?

Me: Malfoy.

They: What does he play?

Me: Julian Albert. A CSI working with Barry. But sometimes he gets mind-controlled and takes on the mantle of “Alchemy.”

They: Who controls him?

Me: Savitar.

They: Who’s Savitar?

Me: Barry.

They: Who’s Barry again?

Me: Flash.

… 

 

Toggl’s “Building a Horse with Programming” comic explained

If you don’t know what this is about, you should first go and check it out.

So, C++ is, for me at least, an intolerable programming language. Everything from the code to the resultant program tends to be as ugly as it gets. More than half the time it feels like it was hacked-together to include everything. However, it has been around for a very long time and you can use it to do just about anything that you could want to do with a programming language. Only, the experience and the result may not exactly be great.

Then we have Java. The main problem with Java is that for a language that aims to be useful for all sorts of applications on all platforms, it’s missing a lot of features that are commonly used by full-stack developers. Very often, when writing programs in Java, programmers end up spending more time than they need to creating new types and methods so that they can use them in the program that they actually set out to write.

Ever since npm and nodejs gained popularity, JavaScript has become one of the world’s most widely used languages and npm is probably the most used package manager of them all. And the thing about Javascript programmers is that they use a lot of external libraries and packages and every once in a while, they add their own package to the global repository just to get a kick out of it. By now there are probably more packages in npm than there are libraries for any other language out there and when you are a JavaScript developer, you really have use them if you want to get any work done. The pinked “Backbone” and “Angular” are references to Backbone.js and Angular.js, two popular JS frameworks.

NoSQL refers to database systems that don’t use SQL and are non-relational. An example is MongoDB, which stores JSON objects grouped into collections. The joke is that the non-relational model doesn’t always expose enough information for you to be able to access your objects without using the abstract api.

COBOL? Well, I guess no one entirely gets it except for its creator.

Lisp has a lot of parentheses. Just google sample codes for lisp and you’d know.

C# is a fairly complete and tolerable language. The problem? Microsoft. Windows. The thing about the costume is that C# is basically Java in a costume (it closely resembles Java in terms of syntax and semantics.) The camel is basically the windows environment. Basically, it means that C# programs don’t always work as intended if not running on Windows.

Assembly doesn’t really offer a lot of language features. There’s a basic set of operations that have to be used for everything. But coding something in such a low level language means you get control over aspects that most languages abstract over. So you can make a really efficient program, hence, the thing about running.

Everyone hates PHP. They say it’s a terrible and unsafe language and has unpredictable behavior. I personally have reasons to really like PHP but I will still go ahead and tell you that most good posts on the subject target aspects of the language that really do suck so yeah some of the hate is justified.

 

SQL Server screwups and how to fix them.

So recently I installed Visual Studio 2017 on a laptop and I installed it with only the ASP.NET and WinForms features. I was working on a webapp and initializing the database when I realized that VS was completely unable to connect to the database. I opened the “SQL Server Object Explorer” and tried to manually connect to the MSSQLLocalDB instance and I got this error.

A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: SQL Network Interfaces, error: 50 – Local Database Runtime error occurred. Error occurred during LocalDB instance startup: SQL Server process failed to start.) (Microsoft SQL Server)

I tried to start the service from the CMD and I kept on getting similar errors. Eventually, I concluded that the installation was corrupted and therefore tried reinstalling LocalDB. Guess what? It got me past this error but introduced me to another. It was something like this.

CREATE FILE encountered operating system error 5(Access is denied.) while attempting to open or create the physical file ‘c:\Users\AnasDatabaseName-asdf5sdfasd5fs5dfs5f.mdf’.

This time, the CREATE Database command was failing because it was trying to create and MDF file in my “Users” folder. I checked the default location for the databases and it was in a sub-sub-sub-sub-folder inside AppData. A bit of Googling told me that this was actually a bug in the program itself and had been fixed in a recent update. So I just downloaded the latest Cumulative Update from the Microsoft site and it did the trick.

 

Who are you?

You’re not your face
Yet it defines you
You’re not your body
Yet it forms you
You’re not your soul
Yet it gives you life
You’re not your thoughts
Yet they drive you

You are none of them
Yet all of them
But none of them
Are all of you.

 

What would it be like to travel at the speed of light?

Imagine an infinitely long flat runway. You are running through it. At the speed of light. Let’s ignore the effects of relativity and resistance. The visible spectrum is painted on the runway, all the way from the start to the finish, meaning there’s infinitely many shades of all the 7 colors of the rainbow painted on the runway, each one easily distinguishable from the next. Yes, we are also assuming this is possible. An infinite number of trees are planted along the edges of the runway.

The speed of light is 300 000 000 m/s. Which means that any objects at a distance of 300 000 000 m from you will only be visible for a second after which you’d already have passed them. Any objects along your path relatively closer to you than the refresh-rate of your brain or your eyes or both, will not be perceptible.

You are standing at the starting point. On both sides of the runway, you can see a row of trees extending as far as the end of the runway, all of them look same age and length and appear to have the same amount of shrubbery. In short, they look identical. Your family and friends came to wish you good luck and are standing right behind you. Along with a whole crowd of people who paid to witness this miraculous feat. You got on your left another in runner, wearing red, who will start exactly one second after you and on your right is a runner, wearing violet, who will start exactly one second before you. All three of you have the same acceleration. All 3 of you are wearing heat and radiation resistant clothing.

The runner on your right has started. You see him become a red streak and disappear. The moment he disappears, you get hit by a wave of heat. Not that you should be looking at him cause after exactly one second you follow. Start running. Immediately after you start running, look at the runner behind you, you’d see him wearing violet instead of red as you get faster and depending on the shade of the red in his clothes, he may or may not completely disappear. This is due to the Doppler Effect.  You will know you’ve reached the speed of light when all you see behind you is an abyss of blackness. You might observe a flash of violet before that happens. The light from anything behind you never reaches you. Your field of vision is limited to 180deg from your immediate left to your immediate right. On your right you can see a purple streak extending all the way from slightly less than 260 000 000 m ahead of you to exactly 300 000 000 m ahead of you. That’s the runner who started before you. That streak is simply multiple images of him running.

If you look down at the painted ground, instead of seeing the colors change smoothly, you’d see them flickering into each other. Kinda like jumping straight from bright red to yellowish orange, because you are moving faster than the time it takes for the brain to “refresh” the image you see. The smaller the angle between your line of sight and the ground, the smoother the transition from one color to the next. Meaning, if you look directly at the ground and then slowly move your eyes upwards, you’d see the change between colors getting smoother, however the rate of that change would keep on getting smaller, and eventually, you’ll be able to see each shade for almost a whole second. But you will be looking at the color of the ground 300 000 000 m away from you.

Now look at the trees. They no longer look uniform and similar. The ones farthest from you still look like they did when you started running but the ones closest to you look very different. They look older and yellower and less leafier. The farther you go, the less leaves you see on the trees and more on the ground and the farther you go, the older they get. If you look at the tree farthest from you and keep on looking at it until you reach it, you’d see it smoothly lose leaves and colors and life.

I forgot to warn you to not look straight ahead. The Doppler’s effect needs to be taken into account also for objects that you’re running towards. Remember that radiation proof suit you put on? It was for a reason. The light from the objects that you are running towards has been blueshifted out of the visible spectrum. Any part of the electromagnetic spectrum travelling towards you now carries an infinite amount of energy. Not only would it be impossible for you to see it, your eyes would probably burn, if not along with the rest of your body. In truth, as soon as you approach a significant fraction of the speed of light, everything in front of you would turn blue and then eventually violet. But the other parts of the spectrum that you shouldn’t really be able to see, will now be somewhat visible. First the infrared waves would make an appearance followed by the radio waves. Yes, they’d look red at first but eventually they might get blueshifted out completely and then there really won’t be anything left for you to see.

In truth, there really won’t be much time between when you start running and when you blackout and also get obliterated as a result of the radiation but I wanted to make a post about what you could see, if you could keep on running at the speed of light for a while. That’s why I didn’t mention the blueshift until the end. There are better posts than I could ever come up with about the same concept but with relativity taken into effect. My favorite one being Relativistic Baseball. Yes I know they set the speed at 0.9c but then again, it’s because they present actual math and wanted to avoid infinities resulting from using c as the speed. An example of such an infinity would be trying to calculate the blueshift of an object approaching you at the speed of light.

The blueshift equation is as follows:

F = f * c / (c-v)

The variable v is the relative velocity of the object moving towards you. When moving at the speed of light towards a stationary object, this v is equal to c. Which means the denominator becomes zero which means we cannot determine the new frequency or as some of you would like to conclude, the frequency is infinite, meaning the wavelength becomes zero. Any photon with zero wavelength would have infinite energy which is not possible.

Sorry for wasting your time.

 

Men In Black 2 – The locker and the marble

In Men In Black, we see J and K chasing down Edgar The Bug to recover the “Arquillian Galaxy” which is a minuscle galaxy inside a glass sphere resembling a marble. As the movie ends, the camera zooms out from J’s car and keeps zooming out and eventually we zoom out of the earth, the solar system and finally the galaxy which is  revealed to be inside another glass sphere which is then picked up by some giant being and used as a playing marble alongside countless others.

In Men In Black 2, we are introduced the the C18 locker aliens, who are tiny creatures, about a few centimeters in height that live inside a locker in NYC. This was slightly different from the Arquillian Galaxy in that the beings were far bigger and their “colony” resembled a fair-sized city. Their origin is unexplained but it is safe to assume that they weren’t always there and were relocated and perhaps recolonized at some point in time prior to the events of the movie. At the end of the movie, J insists on showing telling them that there’s more to the universe than just the inside of a locker at which K proceeds to open a mysterious black door that says “Do Not Open.” As we zoom out of J, K and Frank standing in the doorway, we see a whole array of giant lockers inside a giant station and giant humanoid aliens walking around in it, which basically was meant to show that the humans themselves are living inside a giant locker.

Now what does it all mean together? Do we live inside the locker or the marble or both? Considering both concepts were boldly put forward by the movies themselves and assuming that they haven’t made any continuity errors, it is relatively safe to say that we are inside both. When we zoom out of the locker, we can still clearly see Jay and K and Frank standing in the doorway of the locker and they are scarcely smaller than the locker itself. This suggests that the locker doors are not containers but mere portals to worlds whereas the giant station is kind of an intermediary “world between worlds” just like the forest with pools from Narnia. This portal could be located in virtually any of the planets or worlds or galaxies shown or mentioned anywhere in the trilogy or it could be an extra dimensional thing that manifests itself as a station with lockers to 3D beings.

Building upon the fact that the lockers are portals, we can assume that each portal leads to a separate galaxy considering how all galaxies are supposed to be packed inside marbles and therefore don’t really allow the inhabitants to just fly out of them.