30- (top) and 72-pin (bottom) SIMMs. Early 30-pin modules commonly had either 256KB or 1MB of memory.

A SIMM is an older type of memory module used for RAM in personal computers. SIMM stands for Single In-line Memory Module. It differs from a DIMM (the most predominant form of memory module today) in that the contacts on a SIMM are redundant on both sides of the module. Crop from Image:RAM n. ... Look up RAM and random access memory in Wiktionary, the free dictionary Different types of RAM. From top to bottom: DIP, SIPP, SIMM 30 pin, SIMM 72 pin, DIMM, DDR DIMM Random access memory (sometimes random-access memory), commonly known by its acronym RAM, is a type of computer storage... DIMM is an abbreviation for Dual In-line Memory Module, it is an assembly of several RAM chips on a single PCB for usage in personal computers. ... Redundancy, in general terms, refers to the quality or state of being redundant, that is: exceeding what is necessary or normal, containing an excess. ...

The first variant of SIMMs has 30 pins and provides 8 bits of data (9 bits in parity versions). This article is about the unit of information. ... In the usage in telecommunication, the number of 1 bits in the binary value is counted. ...

The second variant of SIMMs - also called PS/2 after the IBM line of computers in which it was first used - has 72 pins and provides 32 bits of data (36 bits in parity versions). PS/2 can refer to: Headline text IBM Personal System/2, a series of post-PC computers sold by IBM starting in 1987. ... International Business Machines Corporation (IBM, or colloquially, Big Blue) (NYSE: IBM) (incorporated June 15, 1911, in operation since 1888) is headquartered in Armonk, NY, USA. The company manufactures and sells computer hardware, software, and services. ...

Due to the differing data bus widths of the memory modules and some processors, sometimes several modules must be installed in pairs to fill a memory bank. For instance, on 80386 or 80486 systems (data bus width of 32 bits) either four 30-pin-SIMMs or one 72-pin-SIMM are required for one memory bank. On Pentium systems (data bus width of 64 bits) two 72-pin-SIMMs are required. The Intel 80386 is a microprocessor which was used as the central processing unit (CPU) of many personal computers from 1986 until 1994 and later. ... Intel i486 DX2- top view The Intel i486 (also called 486 or 80486) is a range of Intel CISC microprocessors which is part of the Intel x86 family of processors. ... Pentium logo, with MMX enhancement The Pentium is a fifth-generation x86 architecture microprocessor by Intel which first shipped on March 22, 1993. ...

To install a SIMM, the module must be placed in the socket at an angle, then rotated (angled) into position. To remove one, the two metal or plastic clips at each end must be pulled to the side, then the chip must be tilted back and pulled out.

RAM technologies used on SIMMs include EDO and FPM. DRAM is a type of random access memory that stores each bit of data in a separate capacitor. ... DRAM is a type of random access memory that stores each bit of data in a separate capacitor. ...