RAM in the first production models of computers are an integral part of the whole system.Maybe someone else remembers 80286 and motherboards for them.In the first audit includes a huge number of small soldered connectors in which to insert the chip.I added a chip - was a few kilobytes of RAM, though, as a rule, no build-up volume was not engaged.Typically, once the system was bought with a certain amount of memory.And the price of chips has been quite high.However, as the technology of manufacturing semiconductor chips cost components began to fall (the process continues in our time), and it became necessary to create a comprehensive solution that allows without any problems increase the amount of RAM.Thus was created the memory module (now you can hear the slang expression - strap).Since then, it took several decades: alternated standards, improved chip, but the idea remained unchanged.
How does the memory module
distinguish the bar from the other components is very simple: it is a rectangular plate of the PCB on which one or both sides soldered chip.The memory unit may be covered with the metal heat sink that improves heat dissipation.To connect to the motherboard provides a comb copper sliding contacts.The first such decision became known as SIMM, which stands for "Single In Line Memory Module", ie "memory, placed along the same line."For their fixation on the board we created special slots in which each memory module is inserted at an angle of 30 degrees, and then straightened up, tightened.
history of slats
first SIMM-s contained a total of 30 pads, could boast of up to 2 MB ... eight-digit, because of what had to install them in pairs to match the system bus.The development of the famous Pentium processor with a fantastic time for 32 bit memory subsystem required modernization - strap got 72 contacts.Then, until 1997, no radical changes have been made.Increases the volume of chips, no more.Soon, however, it created a new standard - DIMM, which stands for "Dual In Line Memory Module".These modules were copper contacts and a second side, and the number was increased to 84 units per side.In addition, bit increased to 64 bits.By the way, the modern module of DDR2 memory and 64-bit (for conventional single-channel mode).
later time on steel rails to place the chip SPD, which contained information about the possibilities of chips - a simplified auto-configuration.The appearance of the modules with reduced voltage caused developers to create a special "key" - cutout in the terminal block, through which older types of bars (high voltage) physically were incompatible with the new.Rosli frequency increases the amount of memory.Contacts became 184. The memory module has been created for a laptop - it is different from the usual design, allows you to position several such decisions in a small body of the laptop.To improve performance, it was proposed to transfer data at an accelerated rate - so any straps DDR, in which a signal is transmitted optimally.Then any DDR2, a reduced voltage and denser use of the carrier frequency.Currently, the modern computer systems use DDR3.