Will a MK4027N-3 RAM works?

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Will a MK4027N-3 RAM works?

My Apple 1 replica uses MK4027N-1 RAMs so I'm wondering if an MK4027N-3 will also work?

..

Here are some differences I noticed from the datasheet.

MK4027N-1  - 120ns access time, 320ns cycle

MK4027N-3 - 200ns access time, 375ns cycle

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Will a MK4027N-3 RAM work?

I'm currently using Motorola MCM4027AC3s in mine. They match the specs you list and they work perfect so you should be fine.  I think the 4027s are a bit more forgiving than the 4096s but that's just me.  

 

Maximum Access Time = 200 ns - MCM4027AC3 

Maximum Read and Write Cycle Time = 375 ns - MCM4027AC3

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Should still work.

Should still work.

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PROMetheus wrote:I'm

PROMetheus wrote:

I'm currently using Motorola MCM4027AC3s in mine. They match the specs you list and they work perfect so you should be fine.  I think the 4027s are a bit more forgiving than the 4096s but that's just me.  

 

Maximum Access Time = 200 ns - MCM4027AC3 

Maximum Read and Write Cycle Time = 375 ns - MCM4027AC3

 

Do you find the Motorola chips draw more current than the MK4027?  I tried them in my Mimeo to free up some authentic ram and it made LM340-12 regulator run hot where it needed a heat sink.  Same with Intel ceramic RAM.  They worked fine, just drew more current.  Didn't have that problem with MK4096 chips which was how I went on that Mimeo.

 

Cheers,

Corey

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Hmm...

That's a really good question.  The data sheets show an IDD1 of 35mA on MCM4027 and MK4027 vs. 25 mA for the 4096-11 but I don't know what they are really drawing in use.  I'll have to check.  Now, where did I put my IR thermometer...  

 

To the OP, the MK4096N-11 that I see used on original boards show an access time of 350 ns.  Your 200 ns RAMs should be no problem.  

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PROMetheus wrote:I'm

PROMetheus wrote:

I'm currently using Motorola MCM4027AC3s in mine. They match the specs you list and they work perfect so you should be fine.  I think the 4027s are a bit more forgiving than the 4096s but that's just me.  

 

Maximum Access Time = 200 ns - MCM4027AC3 

Maximum Read and Write Cycle Time = 375 ns - MCM4027AC3

 

That's great, thank you!

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