Macintosh SE RAM??

Discussion in 'Apple Collectors' started by ivnj, Apr 22, 2012.

  1. ivnj macrumors 65816

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    Dec 8, 2006
    #1
    Want to replace the ram in my fdhd. The only problem is I don't know how. Got the tools to open it yesterday. Found cool signatures in the back from the dev team. But the rest was dusty. I prayed not to break anything. And after replacing the cover and foil it still boots. How cool. But while inside I was afraid to break anything. So I couldn't get any clear shots of the motherboard.

    Does any one have pictures of the se motherboards. Want to see where the resistor is behind the4 ram slots (where it is and what it looks like). And the difference between that version with the jumper. Trying to tell what board version I have and its hard to get a good look without destroying it.

    So some pics would really help. Thanks, ivnj.
     
  2. MacTech68 macrumors 68000

    MacTech68

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    #2

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  3. ivnj thread starter macrumors 65816

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    #3
    Thanks for being the only helpful reply on the internet so far. Would be cool to see a photo of the jumper also. Anyhow,

    BTW just out of curiosity what would happen if I put in the ram without clipping any resistors (assuming I have the non jumper version).

    1. Would it still boot just not repot the right size of ram??

    2. Or will it fail to boot at all??

    3. Or will it boot and show the wrong size ram but still allow me to boot system 7 and run more apps that require extra ram that would not run before??

    Which is correct??
     
  4. MacTech68 macrumors 68000

    MacTech68

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    #4
    Well, 1 and 2 are correct depending on several variables.

    A long explanation is;

    The drawback is that you need to know the capacity of the modules you're installing OR go through a series of tests to verify what size the modules are.

    So, if you TELL the computer (via the resistors or jumper) that it has 4MB (4 x 1MB modules) when it REALLY has 1MB (4 x 256KB modules) then when you turn the machine on, it should fail with a 'Sad Mac' icon on the screen.

    Conversely, if you if you TELL the computer (via the resistors or jumper) that it has 1MB (4 x 256KB modules) when it REALLY has 4MB (4 x 1MB modules) then when you turn the machine on, it will boot, but only show 1MB of RAM - not a desirable situation.

    Add to that, you have several choices of RAM configurations, so it may be a lot of trial and error - a tad annoying and tedious.

    Bare in mind that a faulty module will also return a 'Sad Mac' icon. :mad:

    When stuck, I used to use a Mac LC which allowed testing of two identical modules to verify their capacity. Finding a working LC these days might be difficult.
     
  5. ivnj thread starter macrumors 65816

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    #5
    This is what I bought.

    http://www.ebay.com/itm/15079896000...NX:IT&_trksid=p3984.m1439.l2649#ht_968wt_1348

    Here's the thing. Simms are so expensive. Anything mac really is on ebay. Even some SE's like 4-500 cuz they're so old. So I don't know the speed. But hardly any 30 pin 1mb simms on ebay anyway so I too the risk. They arrived a few days ago. Memory x also had some but a lot of bad reviews for it so I went with ebay. Also I got good feedback so not a total loss.

    Anyhow 4mb is the max in my fdhd. So I had no choice. The reason I ask is if it turns on but reports the wrong size then all is good. Meaning the ram is good. Cuz the wrong speed won't even boot. So it it works then its good. And I can just leave it like that. And then I can go back to 1mb if I wash later.

    Cuz if it shows a sad mac icon I can remove the 4mb and then reinstall the 4 256 (1mb original factory) simms and it will boot right? Or will it fry something and be sad forever?

    Going back to the old 1mb should make it boot right? If so then no harm in testing the ram. But if it won't boot without clipping something, then there is no point in trying if it won't boot anyway. Cuz If I clip it and it is bad ram then I can't go back to the old 1mb. So I got zero boot. But if it works without clipping anything (even if it reports the wrong size) then the ram is good and resistors can always be clipped later. No harm in leaving it in right? Cuz I'm not buying a crusty old lc just to test.
     
  6. MacTech68, Apr 23, 2012
    Last edited: Apr 23, 2012

    MacTech68 macrumors 68000

    MacTech68

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    #6
    You won't fry anything testing the SIMMs you bought. If they are the ones pictured then they are 70nano seconds RAM - well within spec. The only thing is that they have parity (9 chips instead of 8) but the SE should ignore this factor. You still won't fry anything.

    Give it a go. If it works, cut the resistor for your full 4MB.

    The chips used are Samsung KM41C1000BJ-7 FPM DRAM 5volt so you're good to go!

    EDIT: a word of warning. Be careful with the clips that hold the RAM. Don't bend them out too far or you may break them. They may be white or black DIMM sockets.
     
  7. ivnj thread starter macrumors 65816

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    #7
    That is the part number. But I don't know what speed it is. I only know that is gaurentee not DOA he said. I did read somewhere they said SE doesn't take parity sims. Never knew that is what the 9th chip is for. And 2 chip simms are no good either. But I'll try anyway and see thanks.

    See it says cannot use 2 chip simms.

    http://support.apple.com/kb/SP191

    Also what to remove before sliding out the board? Just power, floppy and hard drive cables? Is that it? The slide board out and add ram?
     
  8. ivnj thread starter macrumors 65816

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    I decided to be brave and do it anyway. Now I got 4mb of ram. Took out floppy, hard drive, and motherboard power cable. Then slid board out and to my surprise I had the tiny black jumper so removed it and installed new ram. Now I got 4mb of ram. Only bad thing was the clips were so tight. Bottom right facing the screen as if board was installed. The bottom slot right side of clip broke. But chips were so tight it stayed in place with the left clip. And 4mb is the max so I never need to open it again. I was scared. But it turned on and no sad mac. Booted right away and now I'm good. Took few seconds longer first time so I was scared. But now it works.

    So I got 4mb now and even says under about this finder total 4096k or whatever. So thanks for all your help. Couldn't of done it without you help, ivnj.
     
  9. MacTech68 macrumors 68000

    MacTech68

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    #9
    Well done, & thanks! Enjoy your SE! :cool:
     
  10. ivnj thread starter macrumors 65816

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    #10
    So the broken plastic tab on the ram slot is not that big a deal if its holding? Or should I be worried?

    And now to get SYSTEM 7 on there. Problem is that even the 7.0.1 smi listed below is to big for a floppy.

    http://download.info.apple.com/Appl...n/Macintosh/System/Older_System/System_7.0.x/

    Could I buy a 50 pin pci scsi for the XP machine I have and use transfer the smi's to the lacie joulie 750mb external HD I'm getting on the 25th. Like with hfs explorer. Or downloading the files and then transfering them to the scsi will make the resource fork disappear. Cuz img's made on sheepshaver in my intel 1.6 late 2006 mac mini don't loose any resource fork when thansfered to a usb flash disk. Then I use winimage to write the disk. Problem is 7.0.1 is too big for a floppy. Or I'd like to download directly to the scsi. But windows XP won't recognize HFS.

    Any ideas?? Thanks, ivnj
     
  11. ivnj thread starter macrumors 65816

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    #11
    Oh and here shots of the jumper and my board. Sorry I forgot to take photos of the clip I broke. And the battery holder is stock. I didn't add that. Surprising after all these years it didn't leak all over the board.
     

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  12. MacTech68, Apr 24, 2012
    Last edited: Apr 24, 2012

    MacTech68 macrumors 68000

    MacTech68

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    #12
    You should be OK with one clip broken - obviously it's not ideal but there isn't much you can do (short of replacing the connector).

    The 7.0.1 download is a disk image containing 1.44MB "DiskCopy 4.2" images of the whole 7.0.1 disk-set.
    The 7.0 download is a disk image containing the 800K "DiskCopy 4.2" images of the whole 7.0 disk-set.

    AFAIK, you won't be able to make 800K disks using a PC or a USB floppy drive, but you might be able to create 1.44MB disks using a PC or USB Floppy (on a PC or Mac).

    I'm not familiar with creating Mac floppies on a PC since I'm lucky enough NOT to need to do so.

    You need to determine which drive you have in your SE. Simply looking at the labeling on the SE's case won't tell you, since third party upgraders may have fitted updated ROMs and a 1.44MB floppy drive without changing the case labeling.

    You then have the problem of whether or not the floppy drive in the SE actually works.
     
  13. ivnj thread starter macrumors 65816

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    #13
    I'm FDHD that's why I can use windows. So 1.44 for me.
     

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