The Rom

The ROM (read-only memory) or read-only memory is the memory that is used to store programs that start up the computer and perform diagnostics. Most computers have a small amount of ROM (a few thousand bytes). Since the ROM also allows random access, if we want to be precise, the RAM should be called RAM reading and writing, and memory ROM read only memory.
Types of ROM:



There are 5 basic types of ROMs, which can be identified as:

1. ROM
2. PROM
3. EPROM
4. EEPROM
5. Flash memory.

Each type has some special features, but all have one thing in common:

The data are stored in these chips are not volatile, which means you are not lost when the computer shuts down.

The stored data can not be changed or failing to require some special operation changed. Recall that RAM can be changed at the moment.

All this means that by removing the source of energy supplying the chip does not mean that the data is irretrievably lost. ROM operation.

In a similar way to RAM, ROM chips contain a string of rows and columns, but the way they interact is quite different. While RAM uses transistors usually to make way for a trainer at each intersection, ROM uses a diode to connect the lines if the value is equal to 1. Conversely, if the value is 0, the lines do not connect at all.