UAC326AEV1 HIEE401481R0001 ABB multi-bus loop module
A single-in-line memory module (SMM) is a type of memory module containing random access memory used in computers from the early 1980s to the early 2000s. It differs from dual-in-line memory modules (DIMMs), the most dominant form of memory module since the late 1990s, because the contacts on the SIMM are redundant on both sides of the module. SIMMs standard in JEDECJESD-21C.
UAC326AEV1 HIEE401481R0001 ABB multi-bus loop module
The earliest personal computer backboards (8088 based on computers, XTs, and earlier (as per atthesuit proceedings)) used receptacle-soaked chips for dynamic random access memory. As computer memory capacity grew, memory modules were used to save motherboard space and simplify memory expansion. Only one additional memory module is needed to increase the computer’s memory, instead of inserting eight or nine single DIP chips.
The initial memory module was built on a ceramic substrate with 64K Hitachi “flip chip” parts and with pins, i.e. single-row in-line package (sip) packaging. [2] There is an 8-bit section and a 9-bit section that are both 64K. Pins are the most expensive part of the assembly process, and Zenith Microcircuits, working with Wang and Amp, quickly developed a pin-free connector that is easy to plug in. Later, these modules were built on ceramic substrates using Fujitsu plastic J-lead chips, and later, they were made of standard PCB materials. SIMMs that use pins are often referred to as SIP or SIPP memory modules to distinguish them from more common modules that use edge connectors.
The first variant of SIMMs has 30 pins, providing 8 bits of data (plus a ninth error-detecting bit equivalent to SIMMs). They were used for AT-compatibility (286 based, for example, on the King Armored Personnel Carrier [3]),386 based, 486 based, Macintosh Plus, Macintosh II, Lepper, Atari STE microcomputer, King VS Minicompany, and Roland Electronic Sampler.
The second variant of SIMMs had 72 pins and provided 32-bit data (36-bit parity and eccentric version). These first appeared in the IBM PS/2 in the early 1990s, and later in the 486 based on the American Intel company’s microprocessor, the Chinese translation is “Pentium”, Pentium Pro, early Pentium II, and other brands of contemporary/competitive chips. By the mid-1990s, the 72-pin SIMM had replaced the 30-pin SIMM and began to be DIMMs.
UAC326AEV1 HIEE401481R0001 ABB multi-bus loop module
ABB DAI03
ABB DAO01
ABB DDI01
ABB DDO01
ABB DLM02
ABB DSAI133A
ABB DSDO115A
ABB DSDX453
ABB DSPC454
ABB DSQC332A
ABB DSQC504
ABB DSQC509
ABB DSQC633
ABB DSRF197K01
ABB DTCC901B
ABB DTDX991A
ABB FPX86-9329–C
ABB GCC960C102
ABB GCC960C103
ABB GDC801B101
