Which RAM Type Is This

[bostonman]

I'm upgrading the RAM in my old Win based oscilloscope and did so in another same model scope; from 256MB to 512MB.

Long story short, this was the RAM I bought for I think $20 off CL (x2 256MB sticks - I didn't want to mix manufactures). Now I want to buy similar RAM, but I'm trying to figure out if this type RAM is exclusively 168 pins (from what I've read). Before I spend the asking prices off eBay, I wanted to confirm I'm purchasing the correct pin count.

Nothing on the label seems to indicate pin count, can someone tell me if 168 is the correct count (physically counting pins didn't seem to add to 168).

[Kim Christensen]

Looks like PC133 RAM can come in two different form factors. (168-pin or 144-pin)

[bostonman]

Okay, so I'm not crazy because that's what I had found.

Unless I'm wrong, I think notch spacing/location defines the pins count, but I seldom dealt with RAM; and haven't dealt with RAM for years.

[wraper]

The only thing you needed to do is googling its part number. https://www.oempcworld.com/OEMPCworld-com/013740.html

[bostonman]

That's what I did and found both 144 and 168.

I wanted to confirm whether PC133 had an exclusive pin count and looks like these are 168. I wasn't sure if it had equal pins on both sides of the PCB; else I would have did a pin count and doubled it.

[Kim Christensen]

PC133 was pretty standard PC RAM back in the early 2000s... I'm pretty sure any PC133 RAM will work for your application unless there is something unusual about your scope. Just get the right formfactor ( 133mm long 168 pin DIMM) which was used in desktop PCs vs the 68mm long 148 pin SO-DIMM which was used in laptops.
Might be hard to find since it's long obsolete.

EDIT: Though you may have to worry about single sided vs double sided PC133:
https://www.eevblog.com/forum/embedded-computing/sram-pc133-double-sided-vs-single-sided-detected-half-capacity/

[wraper]

That's what I did and found both 144 and 168.

I wanted to confirm whether PC133 had an exclusive pin count and looks like these are 168. I wasn't sure if it had equal pins on both sides of the PCB; else I would have did a pin count and doubled it.

The only thing PC133 means is speed grade. There is no confusion with pin count of MT16LSDT3264AG-13EE1 part number.

[bostonman]

I wanted to clarify something just so nobody thinks I didn't use Google prior to my question.

After reading, my understanding went from PC133 being a standard notch and pin count to questioning notch location and pin count. So it was actually the Google research that got me more confused.

Thankfully the person I purchased RAM from before still has a CL ad and is willing to sell another two 256MB sticks for $16.

[wraper]

After reading, my understanding went from PC133 being a standard notch and pin count to questioning notch location and pin count.

It has nothing to do with form factor/pin count. It only means it's 133MHz SDRAM and nothing more.

[Haenk]

Googled that for you:
https://www.ebay.de/itm/175402882183

It's a 133MHz CL2 module (aka the best spec you could ever get), 168pin SDRAM module; 16 chips.
Best is to match with a second one of the same part#, that's the MT... number.
However, if you don't care about speed, it will likely happily pair with another 256GB 16chip-module, be it PC100 or PC133. Buy only big brands like Micron, Samsung, Hynix. (And certainly don't buy 8-chip modules from "some brand", these are often 32x4 based and will not work...)

[SiliconWizard]

Yes it's just SDRAM @133MHz. That would be pretty old. Is this a Tektronix scope?

[garrettm]

It's certainly PC133 SDRAM. But can we see a photo of the entire module? Printers used smaller DIMMs (separate from laptop and desktop DIMMs):

[Haenk]

But can we see a photo of the entire module? Printers used smaller DIMMs (separate from laptop and desktop DIMMs):

Why add unnecessary confusion to this topic? The label shown has a unique part# on it.

[garrettm]

But can we see a photo of the entire module? Printers used smaller DIMMs (separate from laptop and desktop DIMMs):

Why add unnecessary confusion to this topic? The label shown has a unique part# on it.

To show there are more than two module types for SDRAM? I thought that obvious from context--I simply provided photos of my own to show an example of the slot and module for comparison. I fail to see how that adds confusion to anything.