by Brandon Roberts
Alan Turing Information
The first generation of computers
It started in 1942-1955 .
The computers were to big.
They used up a lot of energy.
They heated up very quickly because there were thousands of vacuums.
They weren't very reliable.
They needed air conditioning.
They needed to be fixed a lot.
Imputs and outputs
You use input devices all the time when you are going on a computer such as a mouse and a keyboard. There are a lot more inputs that send data to the computer. Here is some
ROM is an acronym for Read-Only Memory. It refers to computer MEMORY chips containing permanent or semi-permanent pre-recorded programs. Unlike RAM, ROM is non-volatile. Even after you turn off your computer, the contents of the ROM remains available.
Almost every computer comes with a small amount of ROM containing the boot FIRMWARE. This holds just enough information so that the computer can check its hardware and load its operating system into RAM. On a PC, the boot firmware is called the BOIS.
Originally, ROM was literally "read-only". To update the programs in ROM, people had to remove and physically replace their ROM chips. Contemporary versions of ROM allow some limited rewriting (referred to as a flash update, as well as the dynamic side of the ROM, which can be written to by the OS), so you can usually upgrade firmware such as the BIOS by using installation software. Rewritable ROM chips include PROMs (programmable read-only memory), EPROMs (erasable read-only memory), EEPROMs (electrically erasable programmable read-only memory), and a common variation of EEPROMs called "flash memory".
RAM stands for Random Access Memory. RAM is the place where your computer temporarily stores its operating system, application programs, and current data, so that the computer's processor can reach them quickly and easily. When people refer to your computer's memory, they mostly mean its RAM, and it is volatile. Not volatile in the common term, as it won't catch file or explode. Volatile in this instance means that when you turn off your computer, anything in RAM disappears or is erased.
Desktop computers usually come with 16 or more MEGABITESof RAM, usually increasing in multiples of 8 megabytes. If you use graphic applications, you probably have 32, 64 or more megabytes of memory. Most personal computers are designed so that you can add more RAM modules up to the limit imposed by the motherboard.
If you add more RAM to your computer, you reduce the number of times your processor must read data from your hard disk (Virtual Memory). This usually allows your computer to work considerably faster.
Again, RAM is volatile. It requires a steady flow of electricity to maintain its contents, so data stored in RAM stays there only as long as your computer is running. As soon as you turn the computer off, you lose everything that was in RAM.
When you turn your computer on again, your computer's boot firmware (called a BIOS on a PC) uses instructions stored semi-permanently in ROM chips to read your operating system and related files from the disk and load them back into RAM. On a Personal Computer, different parts of RAM may be more or less easily accessible to programs.
The motherboard is a sheet of plastic that holds all the circuitry to connect the lots of
components of a computer system.