CYBERSLEUTH
05-20-2001, 11:37 PM
I have a PC100 memory module with SDRAM memory chips on my module bearing the markings:
SD64420AT-7
16MBx8 - 02138
What do each of these markings mean and how can I identify the manufacturer of these chips?
I am leaning towards declaring them Siemens or Samsung manufatured for Siemens. The part number is very similar to Siemens chip numbering system, yet it doesn't come up in a search of Siemens' site for both current or discontinued part numbers. More importantly, I wonder if this chip is rated at 7ns or 70ns? It would seem that according to the PC Guide: "DRAM chips are usually marked with their speed via a suffix at the end of the part number." The guide would have me believe that they are 70ns chips based on the "-7" suffix as opposed to "7" or "07" or something like that that might suggest they are, in fact, 7ns chips. Unless this marking would have to refer to 7ns chips because they are in a 100MHz module designed for PC100 that I can't imagine as using older 70ns chips any longer (though anything is possible) then a literal interpretation of the marking would mean that I have 70ns chips based on the following:
"If you look at the chips themselves, you'll see something like "-6" or "-60". This usually means
60 nanosecond DRAM. The suffix found on SDRAM chips is often "-12", "-10" or "-07".
Note that older memory running at 100 or 120 ns also used "-10" and "-12" sometimes. This
memory hasn't been used in years so there really shouldn't be any confusion between the two
types. However, 70 ns memory uses "-7" and this can be readily confused with 7 ns
SDRAM memory if you are not careful.
In general, is there some guide out there to teach me how to read and identify the
markings on SDRAM memory
chips?
Any and all assistance most appreciated.
I did find the following list for anyone trying to help:
A: Nanya
C: Infineon/ Siemens
E: Elite
F: Fujitsu
G: Goldstar, LG
H: Hitachi
I: IBM
L: Mosel Vitelic
M: Micron
N: NEC
O: OKI
S: Samsung
T: Toshiba
V: Vanguard
W: Winbond
X: TI
Y: Hyundai
1: Mitsubishi
2: Motorola
------------------
Cybersleuth
SD64420AT-7
16MBx8 - 02138
What do each of these markings mean and how can I identify the manufacturer of these chips?
I am leaning towards declaring them Siemens or Samsung manufatured for Siemens. The part number is very similar to Siemens chip numbering system, yet it doesn't come up in a search of Siemens' site for both current or discontinued part numbers. More importantly, I wonder if this chip is rated at 7ns or 70ns? It would seem that according to the PC Guide: "DRAM chips are usually marked with their speed via a suffix at the end of the part number." The guide would have me believe that they are 70ns chips based on the "-7" suffix as opposed to "7" or "07" or something like that that might suggest they are, in fact, 7ns chips. Unless this marking would have to refer to 7ns chips because they are in a 100MHz module designed for PC100 that I can't imagine as using older 70ns chips any longer (though anything is possible) then a literal interpretation of the marking would mean that I have 70ns chips based on the following:
"If you look at the chips themselves, you'll see something like "-6" or "-60". This usually means
60 nanosecond DRAM. The suffix found on SDRAM chips is often "-12", "-10" or "-07".
Note that older memory running at 100 or 120 ns also used "-10" and "-12" sometimes. This
memory hasn't been used in years so there really shouldn't be any confusion between the two
types. However, 70 ns memory uses "-7" and this can be readily confused with 7 ns
SDRAM memory if you are not careful.
In general, is there some guide out there to teach me how to read and identify the
markings on SDRAM memory
chips?
Any and all assistance most appreciated.
I did find the following list for anyone trying to help:
A: Nanya
C: Infineon/ Siemens
E: Elite
F: Fujitsu
G: Goldstar, LG
H: Hitachi
I: IBM
L: Mosel Vitelic
M: Micron
N: NEC
O: OKI
S: Samsung
T: Toshiba
V: Vanguard
W: Winbond
X: TI
Y: Hyundai
1: Mitsubishi
2: Motorola
------------------
Cybersleuth