Memory chip I.D.

[Greg95035]

I'm looking for spec's on a memory chip on some 72 pin simms. I've searched and had no luck finding it. The chip is marked as such
Japan F020
0017 SNN
51131656FTD6

Any help would be greatly appreciated

 

[bum_jcrules]

Do you know which form of memory it is?

Fast Page?
EDO?
SDRAM?

From your post I take it that the model number is the 51131656FTD6 or some part of it. If that is correct, it could be NEC.

If you could post a picture somewhere and link it here we could look at if and continue searching for it.


You've got me stumped here for now... Unless you can give me a little more info.

Why are you looking for the specs on it?

<font color=red><b>Come to the <A HREF="http://forumz.tomshardware.com/community/modules.php?name=Forums&file=viewtopic&p=45775#45775" target="_new">THG Gathering/LAN party</A>

 

[fastingsetiman]

Hi. Here's some help or no help. Depends.






by: Tony Araujo

How to Describe the Memory You're Looking for
The purpose of this guide is to help you identify and describe your type of memory..
1. The Part Number of Your Chips

2. The Speed of Your Chips in Nanoseconds

3. The Package Type of Your Chips

1. Chip Part Numbers*
This section will help you decipher what themarkings on your memory chips mean. Memory chips are usuallymounted on various kinds of modules, like SIMMs, which aredesigned to work in computer systems. Often the memory module asa whole will have a part number, and the memory chips that aremounted on the module will have different part number(s). Toreceive a quote for memory you would like to sell, the chippart number (not the module part number) is by far mostimportant. The chip part number, along with the number of chipsper module, allow us to determine the function and capacity ofmemory.
Memory chips tend to have 2 or 3 lines of text on them thatinclude a part number, speed, and date code. Most part numbersstart with a two or three character abbreviation that identifiesthe manufacturer, such as HM (Hitachi), M5M(Mitsubishi), TMS (Texas Instruments) or MT(Micron Technology).

The numbers (and sometimes letters) that follow describe thememory configuration of the chip, for example HM514400is a 1Mx4 configuration.

After the part number, there is usually a "A","B", "C", or "D." This is how somemanufacturers grade the performance of the memory, with"A" being most superior and "D" least, e.g. HM514400A.Manufacturers normally have very stringent requirements on allthe memory they produce, so all grades should perform equallywell in personal computers. Also, be aware that somemanufacturers, especially Micron and Texas Instruments whose partnumbers almost always end in "DJ", do not use a letterto grade their parts.

In many cases, there will be an additional letter that codes thepackage type of the memory, e.g. HM514400AS. In thisexample, "S" stands for SOJ-type packaging.

2. Speed
Speed of the memory is an important factor thathelps determine market value. Carrying over from the previousexample, a 70ns chip may be encoded at the end of the partnumber, e.g. HM514400AS7. In this case, the"7" stands for 70ns. Sometimes there is a dash beforethe speed marking, e.g. KM44C1000AJ-7, and other times the speedis printed on a line above or below the part number. If the speedis printed on a separate line, a dash usually precedes the speednumber. For most common memory chips, speed ranges from 50ns to200ns. The trailing zero is commonly left off, so you may see "-6","-7", "-8", "-10", or"-12", which represents 60ns, 70ns, 80ns, 100ns,and 120ns respectively.
On most chips, there is a date code printed above or below thepart number. The date code indicates when the chip was made, mosttypically in a year and week format (such as 9438 for thethirty-eighth week of 1994). Often, the decade's"place" will be left off. For example, 438 may alsorepresent the thirty-eighth week of 1994

Common Part Numbers*On all types of ram
To ease readability, the table lists part numbers without speed or grade information. The real chip part numbers will look a little longer. A couple of examples of 1Mx4's: "HM514400ALTT7", or "KM44C1000AJ-7
None parity=x32 and parity=x36 1mx32=4 1mx36=4 2mx32=8 2mx36=8 4mx32=16 4mx36=16

256x4 1x1 1x4 4x1 4x4 2k 4x4 4k
Hitachi HM514256 HM511000 HM514400 HM514100 HM5117400 HM5116400
Samsung KM44C256 KM41C1000 KM44C1000 KM41C4000 KM44C4100 KM44C4000
Mitsubishi M5M44256 M5M41000 M5M44400 M5M44100 M5M5117400 M5M5116400
NEC 424256 421000 424400 424100 4217400 4216400
Toshiba TC514256 TC511000 TC514400 TC514100 TC5117400 TC5116400
TI TMS44C256 TMS4C1024 TMS44400 TMS44100 TMS417400 TMS416400
MicronTech MT4C4256 MT4C1024 MT4C4001 MT4C1004 MT4LC4M4B1 MT4LC4M4A1
Hyundai HY534256 HY531000 HY514400 HY514100 HY5117400 HY5116400

Most major chip makers use part number schemeslike those above, where information about the chip is more orless encoded in the part number. However, some IBM part numbersfollow a less self-explanatory scheme. Older IBM part numbersgenerally follow the pattern: NNLNNNN (where "N" is anumber, and "L" is a letter) as in 89X8922or 02G2871.
3. Chip Packages
SOJ or Small Outline J-lead.
By far the most common package type is the SOJ. SOJ chips come inthree different sizes: 300, 350, and 400 mil. The mil sizeactually refers to the width of the chip in thousandths of aninch. All other things being equal, the same chip in a largerpackage tends to have less market value.

A more modern but less commonly seen chip package is the TSOP.TSOPs are very thin, compact packages that take up a minimum ofspace. While their small outline shows how dense memory can bemade, TSOPs are more likely to be susceptible to physical damagefrom rough handling. TSOPs come in 300 and 400 mil sizes.

DIP or Dual Inline Package.
The DIP was more widely used before the SOJ became the favoredpackage type. DIP leads often go through the PCB board, incontrast with the surface mounted SOJ and TSOP. DIP leads aresometimes trimmed, which can reduce the market value of the part.
ZIP or Zigzag Inline Package.
The ZIP is also commonly seen on older memory products. They arealso favored in applications where board space is limited. Aswith DIPs, ZIP leads are often trimmed to fit. This may reducethe resale value.
PLCC or Plastic Leaded Chip Carrier.
The PLCC is typically only seen in lower capacity configurations,usually 256kx1 or more rarely 1Mx1. It is distinguished by havingleads on all four sides.
Modules
The two most common types of memory modules are the 30 pin and 72 pin Single Inline Memory Modules or SIMMs.
30 Pin SIMM.



The most common varieties of 30-pin SIMMs are 256kx8, 256kx9,1Mx8, 1Mx9, 4Mx8 and 4Mx9 although 16Mx8 and 16Mx9 are also possible. You will typically find either 2, 3, 4, 8, or 9 memorychips on 30-pin SIMMs. Any given 30-pin SIMM is likely to be populated with identical memory chips, except the 3-chip SIMM.3-chip SIMMs are likely to have 2 chips of the same type, and a third parity chip which is different from the other two.


72 Pin SIMM.



The most common varieties of 72-pin SIMMs are

4MB modules:1Mx32, 1Mx36
8MB modules: 2Mx32, 2Mx36
16MB modules: 4Mx32, 4Mx36
72-pin SIMMs that do not have parity (x32)usually have only one kind of chip per module. For example, a2Mx32 (8MB) can be constructed with 16 chips of 1Mx4 (such as a424400-70). 72-pins with parity are likely to have two varietiesof chips on board. For example, a 1Mx36 usually has 8 chips of one type (1Mx4, like a 424400-70) and 4 chips of another (1Mx1,like a 421000-70). When requesting a quote, it is important to note all the different chip part numbers on each SIMM, including parity chips.
Other SIMMs
Less common simms include 40, 64, 68 and 80 pinSIMMs. The 64 pin SIMM looks like a smaller 72 pin SIMM and is easily confused for one. Some 64 pin SIMMs function like 30 pin SIMMs while others function like 72 pin SIMMs.

DIMM or Dual Inline Memory Module
Some recently designed higher-end computers use DIMMs, which are often 168 or 200 pin. Dual inline memory module.
SIPP or Single Inline Pin-leaded Package
Many older personal computers and workstationsused SIPP memory, which look like SIMMs with pins instead of an edge connector. This design was not as well received as the SIMMs because the pins tended to bend or break easily.