RAM chip replacements

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RAM chip replacements

I see a lot of fans in Apple vintage groups not liking MT Ram chips .. what are some of your recommendations please for ones that are considered better then MT to replace on an Apple IIe??

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Why?

Why would you want to preëmptively replace anything at all?

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I see a lot of fans in Apple

I see a lot of fans in Apple vintage groups not liking MT Ram chips .. what are some of your recommendations please for ones that are considered better then MT to replace on an Apple IIe??

Pretty much anything.  

But, as robespierre said, pre-emptively replacing anything stands a greater chance you'll make your computer worse, than better.

I have several machines with MT branded RAM.  Some have had failed chips.  I just replace the failed ones and carry on.  The others are still working fine. 

It's better to carefully de-solder one failed chip than risk damaging the board by attepmting to desolder every one of them.

 

 

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I may be wrong...

...But I think they are much more difficult to replace on the IIc because the pads tend to lift easier.  Maybe true for the IIe as well, but IDK.  But to answer your original question, I believe there are many manufactures.  OKI, for one, is a better brand than mT.

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I've been pretty lucky so far

I've been pretty lucky so far but just gathering info now in case I have to replace some that may go bad soon ...

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tiktok4321 wrote:...But I
tiktok4321 wrote:

...But I think they are much more difficult to replace on the IIc because the pads tend to lift easier.  Maybe true for the IIe as well, but IDK.  But to answer your original question, I believe there are many manufactures.  OKI, for one, is a better brand than mT.

Thx .. just trying to be ready when a couple chips do go bad ...

 

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baldrick wrote:I see a lot of
baldrick wrote:

I see a lot of fans in Apple vintage groups not liking MT Ram chips .. what are some of your recommendations please for ones that are considered better then MT to replace on an Apple IIe??

Pretty much anything.  

But, as robespierre said, pre-emptively replacing anything stands a greater chance you'll make your computer worse, than better.

I have

Thx and sorry re I did mean replace when they do go bad ...

 

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Thlorian wrote:I've been
Thlorian wrote:

I've been pretty lucky so far but just gathering info now in case I have to replace some that may go bad soon ...

You can also use 41256 chips in place of the 4164.  They're usually cheaper and easier to find.  And often way more reliable.

They're 100% pin compatible - just clip off pin #1.  It's not connected in the 4164 but sometimes PCB manufacturers used that hole as a convenient via.

 

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Use 256K DRAMs as-is. Please do not clip off any pins!
baldrick wrote:
They're 100% pin compatible - just clip off pin #1.  It's not connected in the 4164 but sometimes PCB manufacturers used that hole as a convenient via.

 

Don't clip off pin 1 -- it's absolutely required for compatibility.

On a 256K DRAM pin 1 is an additional address bit, an input.  The motherboard has pin 1 connected to a power rail, so it just behaves like that particular address bit is a constant 1-bit so it behaves consistently.  If you clip off pin 1 then that address bit will be vulnerable to noise, causing erroneous accesses to the wrong addresses.

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