ID-ing RAM Chips (Datasheet?)

[Terry Yager]

Can anyone help identify these chips, or point me to a datasheet?

AA1M200P-08H
NMBS 8939

They're 18-pin ceramic DIPs, but I can't find any info. Are they 4-bit x 256Kb, 1-bit x 1Mb, sum'n else, or what?

--T

[carlsson]

I searched through a multitude of online databases. Only one listed that type of chip, but referred to a PDF on another site which declined that a such document existed. All the others at best refer to a Zener diode with a similar part number. Maybe someone else has better luck than me, or knows what to search for. I suppose NMBS indicates who manufactured it?

[Terry Yager]

MeToo. I searched all the datasheet archives I know of, no joy. I believe that 18 of 'em add up to 2Mb + parity. The 8 x 1Mb chips I'm used to seeing are 20-pin packages. I also found an AA1M204P-08, which is a 4 x 256Kb, 18-pin, and an AA1M100, which is a 1 x 1Mb, 20-pin, so the ones I have must be in the same family.

Any idea what the NMBS means? Some of the other chips are so designated too.

--T

[nige the hippy]

The two AA s arent a motorola logo are they? In which case the chip could be an IM200P.

Doesn't immediately help because the data sheets for one of them aren't online either, but they do appear to be rams

these people have 6 (probably)100nS ones

http://www.electrospec.com/semiconductor/search1.asp?parts=1&PartNum=IM200P%2D10NMBS

try motorola semicons??, or if you can work out a pinout, there may be an equiv.

[nige the hippy]

there is another one, AAA LM200P

if you do a google, it comes up with a 1MB dram (but you already know that!), probably an editorial ad from the ieee magazine in 1990 (agrees with date code of end of 1989), but it requires subscription. the z and J suffixes don't help either.

[Terry Yager]

Nope, not Motorola. From what I can tell, the NMBS is the brand, but I'm klewless...

--T

[ribbets]

try www.digchip.com Couldn't match the AA number but NMBS 8939 does have a listing (not much info)
Several mentions about this company in the IBM archive

[Terry Yager]

Yeah, I saw the IBM stuff, mostly about how crappy thier memories are and why they shouldn't be used in an IBM.

--T

[Elar]

AAA 1M200 seems to be 1M x 1 device:
http://www.ic-assess.net/pdf/mz1.pdf

[Terry Yager]

AAA 1M200 seems to be 1M x 1 device:
http://www.ic-assess.net/pdf/mz1.pdf

Thank you, that helps. Still could use a datasheet or a pinout (preferably not in Chinese).

--T

[modem7]

From one of my many data books:

AAA1M200P08H

Manufacturer = NMB Semiconductors
Technology = CMOS
Config = 1M x 1 bit
Access Time = 80nS
Write Cycle Time = 150nS
Output Type = 3 state
Vcc = 5 V
Package = DIP
Operating Temp Range = 0-70 degrees C

PINOUT
-------
1 = Din (data in)
2 = WE (write enable - active low)
3 = RAS (row address strobe - active low)
4 = NC (not connected)
5 = A0
6 = A1
7 = A2
8 = A3
9 = Vcc (+5V)
10 = A4
11 = A5
12 = A6
13 = A7
14 = A8
15 = A9
16 = CAS (column address strobe - active low)
17 = Dout (data out)
18 = Vss (ground)

[Terry Yager]

Perfect! Thank you.

--T