Informatica per le Digital Humanities

Stored Program

The Stored Program implies that both operations and operands can be stored in the same place. Thanks to this organization we can throw both the operation and the operands in the same place without getting confused with numbers. To understand how we can do this, we need to keep concepts distinct: operations, operands, storage and place.

→3+2 352

Place: inside the computer

We have to remember that there is always an organization that always characterizes every effort we are pursuing in our computer that comes from the matrix: organizing things in a rectangular (matrix: rows and columns), we have a better organization. If we need to store numbers, we are going to store them in a matrix form: it is a good form because we apply once again the cartesian principle to the matrix of numbers. Each position of the matrix is occupied by a number (just like each book occupies a spot in a bookshelf). We can recognise substructures of the matrix. A row can be called a

“word”. The size/width of the bookshelf is the size of the word, so the storage space will be characterized by how wide it is. The wider the shelf, the more words we can put on one row; the wider the memory, the more numbers we are able to put inside it.

We don’t actually find all these numbers, but only 1s and 0s. Each position in this matrix is 0 or 1.

Nowadays, our computers work with these “shelves” where we store 0s and 1s, whose length is either 32 or 64 bit: this means that on each shelf we can have 32 0s and 1s or 64 0s and 1s.

A bit is the smallest quantity of data we can work with in the realm of computer science and it is either 0 or 1. When we have 8 bits, we can call that set a Byte. The fact that 8 bits compose 1 Byte is a choice: it was a design choice inside a pioneering microprocessor created by Federico Faggin, Marcian “Ted” Hoff Jr., and Stanley Mazor in the early 1970s (The Intel 4004). Thanks to the success of their processor, their

Choice became a standard. We cannot distinguish between operations and operands but some numbers represent operations and some other operands. How do we organize them in order to keep the distinction? We decide that for each "word", the first 3 bits represent the operators, and the others represent the operands. The distinction is positional, it depends on the position where these bits are placed. The point of distinction is a choice; it is arbitrary. Through this organization we are able to implement the Stored Program: both operands and operations can be stored in the same place, because both operands and operations are bits stored inside words. We manipulate operands with operations. [The 3 is manipulated through an operation: it decreases to 2]. If the operation itself is a sequence of 0s and 1s inside the memory, the Stored Program paradigm enables us to manipulate operations too, meaning that we can change numbers with operations, but since the decrease is also a series of bits inside.

The memory, we can manipulate those bits to change the operation into something else. The same way in which we manipulate operands can be applied to operations. We can change the decrease into "double", so that we do not have decrease anymore, but we have double, so instead of going from 3 to 2, the operands go from 3 to 6 because the operation has changed.

There is a place issue: where do we put everything in the storage place? We distinguish one row from the other because the mathematics of matrices offers a solution: create indexes, indicating rows and positions inside them. Index helps us create an address within the system to orient ourselves inside this matrix of bits. We have a new group of numbers dealing with addresses inside the storage space. It is binary: we do not really have 0,1,2,3..., but we have sequences of 0s and 1s. The addresses are also numbers, so we can store them inside the matrix.

The Stored Program paradigm enables us to deal not only with the operands, the

Data we need to work with as numbers, not only with the operations with which we manipulate those numbers as numbers, but even where we are storing these operations and operands and the numerical address that can be turned into numbers 4527 place, operation, operands. The Stored Program enables us to manipulate operands, to manipulate operations and manipulate addresses.

Through the Stored Program we elaborate data (ex. apply a filter to a photo or add a slide to a presentation), create and modify programs (ex. download an app, update it or buy a new filter, manipulate the software itself, because a program is just numbers inside a storage space) and transfer data and programs (ex. from the desktop to the usb pen).

What is the difference between Microsoft Word and a .docx file? Microsoft Word is the program we use to manipulate document files. This is the distinction (operations: open, save, close, change font, erase…) and between program data.

What is the difference between a program and a document?

They are both files, we download them in the same way: sets of bits.

File is a way to organize documents. The bits that constitute the software Microsoft Word are in the storage space.

We have different kinds of files we can work with: .docx; .m4a; .jpg.

What comes after the dot in the file name gives us information about what kind of file we are dealing with.

A file is a group of bits that are logically treated as a unit. A file may be comprised of data, program instructions, or addresses.

What does it mean "to be treated as a unit"? It is a matter of placing. In the logically real world, inside the storage space of computers a program could be anywhere, it could be divided into pieces scattered everywhere in the storage space as long as the file system can recover them and the computer can put them together and execute the program to work on the device. Physically bits can be everywhere, but when it comes to running the program, the computer is able to recover all the pieces and

treat them as a logical unit.

- What does it mean for a file to be comprised of addresses? When we use a computer, we use folders: they are files too, they are just sets of addresses organizing files in hierarchical order. All of this constitutes what we call computer memory: it holds the bits.

Memory

The term "memory" comes from the Ancient Greek verb "mimnesko", which means "I remember" and "mimnesko" comes from the root "mnè" that comes from the term "men" that meant "the mind". Going through the etymological root of the word "memory", we end up with the concept of the mind.

We also have another word that is connected with the concept of memory: "record", it comes from the Latin word "Re-cordis"; the root of the word "cordis" is "cor", which means "the heart". One important part of the meaning comes from the radical

“Re-cordis”. The computer synthesises in its digital ways both the mind and the heart we use when we remember things. One key aspect that characterises remembering is time: we remember now a past event, not the future. Re in general gives us the idea of something that we re-take, remember about, record and there is a tension between the action of remembering that is happening now and the object of remembering which is in the past. We have different layers when we talk about a past event that has been remembered now.

We have an event, but we can remember maybe through a description of the event; there is a person who accesses the description and by means of that description, he/she remembers.

What is really an event? An event happens, there are people in a place, with their bodies, their faces, their voices. A description of an event is different: the event happened, there were people in a place, with their bodies, their faces, their voices. There is a temporal distinction between an

Event you are living and the description of it. The person accessing the description is important: we need people interacting with the description of the event for any sort of memory, a remembering of the event to take place.

There is a relation between the person accessing the description and the content of the description, because people remember because there is a specific relation between the content of that description and the person remembering that event. A person cannot remember an event in which they did not participate.

Things are different when we change the audience to which we show a description. Memory is intrinsically an interacting thing: memories are not only about a single person, but they can be about a family, a nation, a culture, the human race. Creating a record of a past event (ex. anthropologist record) allows remembering in the future. If we are able to keep these records of past events for a long time, we can set up a system of records (remembering in the far future).

In the future, there is a relation between the person accessing the description and the container of the description. In order to have a record of a past event, there needs to be a record of the event in the first place. Records can be damaged by time: time is also the degradation of material objects. Is a person still able to access the description of an event? Will the container of that description stand the test of time? Digital technology helps us in this sense: there are so many digital technology devices, memories, built to hold bits inside of them for a long time. They contain numbers.

We use our brains to remember things, but our memories are not perfect, we forget things. The idea is that we do not have to remember anything anymore: we turn everything into digital descriptions of events, which are numbers, stored in digital technologies. We need computers to insert devices into it (ex. USB key) and only with a working computer we can access the 0s and 1s stored in the key, which then turn into images.

In the far future will people be able to access these 0s and 1s to transform them into images? Time is still an issue, there is no guarantee we will be able to maintain the encoding that opens the document.

Last time we talked about memory, it's not only a device inside our computers to record data in the shape of numbers, but also as a collective memory for societies and humanity since we're trying to warn our future descendants against some dangers like nuclear waste, for instance.

The problem might be that the encoding we have now that is agreed upon today, may not be still there in the future) how can we leave a message that will still work in 10.000 years?

We have different entities stored in our computer memory: some bits work as operands, meaning they are representing the data we store in our computers and we can process (images, sounds, texts translated into numbers then stored inside our computer memories = data); some other numbers represent not data but operations.