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Sixthview

Attempt, Repair or Scrap? 64K Memory Expander

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First post on here...  Coleco nut in my youth but nostalgia kicked in and I have been messing with my ADAM for about a year now.

So in a box at my mother's house, I found my old memory expander.  But it has seen better days.  

I am wondering what others think... 

  1. Should I try it out before I do anything? (worried about messing the ADAM up permanently) 
  2. Should I put new caps on first?  (I am an amateur at soldering, but I think I can get through it if I know what caps I need)
  3. Just throw it out?

 

 

20201004_184557.jpg

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7 minutes ago, Sixthview said:

First post on here...  Coleco nut in my youth but nostalgia kicked in and I have been messing with my ADAM for about a year now.

So in a box at my mother's house, I found my old memory expander.  But it has seen better days.  

I am wondering what others think... 

  1. Should I try it out before I do anything? (worried about messing the ADAM up permanently) 
  2. Should I put new caps on first?  (I am an amateur at soldering, but I think I can get through it if I know what caps I need)
  3. Just throw it out?

 

 

20201004_184557.jpg

Definately don't plug it in without replacing the caps.  I don't know the value off hand but it should be marked ?????

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Assuming they are all the same, I think they are 104s.  Specifically marked 104Z (T) - The t is in a circle below the 104Z.

I know I have 104s.  Can I replace with modern caps whether Ceramic or Metal Film or should I search out some old stock?

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A definite yes on replacing those,Afterwards you should get positive results

Some people like to replace with metal film,Then again OEM should be okay as well

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24 minutes ago, Sixthview said:

Assuming they are all the same, I think they are 104s.  Specifically marked 104Z (T) - The t is in a circle below the 104Z.

I know I have 104s.  Can I replace with modern caps whether Ceramic or Metal Film or should I search out some old stock?

Sounds fair to me, BUT it depends on the difference on the Z or s designation.  If not interchangeable, you could smoke something.  I am not qualified to know the difference and I have been looking and not seeing what the difference is.

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So I found this about the "Z"

The letter Z donates a tolerance of +80 percent and –20 percent. That means the capacitor, which is rated at .1 μF, might be as much as 80 percent higher or 20 percent lower. See below for a list of letter-style tolerance codes.

 

I don't have Z's.  I have J's.  I also have some multilayer ceramic which are perfectly small and would fit the leg holes super smoothly...  I'm just hesitant to use them.  Not sure if the tolerance would really matter all that much.

 

And I think the T in a circle may just be for the temperature which if I am using new stuff, I am not all that worried about.

 

 

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Those caps are usually just bypass caps for each of the digital chips.  They really don't need to be close tolerance.  Any cap with low ESR should work.  Ceramics are of course a sure thing since that's what it already has.

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I went on ebay and after some searching for a seller that can get them to me within 2 weeks, I found a set.  More than I wanted to spend but it is what it is.  

Thinking maybe I should pickup a new tip for my weller...  This stuff makes me nervous.  

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Posted (edited)

Okay...  I got all the caps on and I think I did okay.  Looks a little funny with those little guys on there.

Set up my second system to test it... Hoping it doesn't blow.

And, what could I use to see if it is working?  Is there a program that counts/tests the ram?

20201009_172327.jpg

Edited by Sixthview
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There are 2 programs that will do the job for you and IIRC they are both called RAMtest... one by Orphanware that was released in the 80s and the other released a couple years ago by Eric Pearson. You can download the disk images from www.adamarchive.com and hopefully you have a means to transfer to an Adam media. If not, contact William Hicks at the Adam Archive for help.

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I have a Microfox SD so I will dl it and give it a try. 

I plugged it into my backup system and nothing blew up so here's hoping it fully works!

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27 minutes ago, Sixthview said:

I have a Microfox SD so I will dl it and give it a try. 

I plugged it into my backup system and nothing blew up so here's hoping it fully works!

There is a Filemanager program on the VDD.  When it runs it will tell how how much ram you have.

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