Mac 512k and SE "developer" units?

Discussion in 'Apple Collectors' started by crecords, Jan 13, 2014.

  1. crecords macrumors newbie

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    #1
    I just purchased a Mac 512k and a early SE computer. They were sold at auction with a note stating that they were developer computers released months before being sold to the public. If this is the case would this make them more valuable? I have not received them yet so I can not look up the serial numbers or take a look inside. The 512k has a hyperdirve also! It also boots to a checkerboard screen which it looks like that could be a bad capacitor. They obviously need cleaning, I would like to at least get the 512k working. They have the original packaging and bag also which is great. After shipping and fees I will have paid a little over $200 which I hope was a good decision. Any thoughts?
     

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  2. MacTech68 macrumors 68000

    MacTech68

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    #2
  3. crecords thread starter macrumors newbie

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    developer

    Yes I realize that is not the serial number, I am anxious to look up the actual numbers when they arrive. I looked up the name on the shipping label and in his professional profile he programmed the Prodigy installation disk for the Mac in 1987 but that does not explain the earlier model. If either one or both units turn out to be pre-release would it dramatically change the value? Either way it will be fun to get at least one working.
     
  4. tdiaz macrumors 6502

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    #4
    That's all 100% retail channel stuff. Other than a nice collection of items, that's it.

    A "developer" 512K wouldn't really exist. It's the same thing as the 128 with just more RAM. Perhaps someone has a prototyped motherboard. Doubt it, though. Not in a system that has a retail box, that came through a retail channel.

    Yes, the original owner could have been a "developer", and bought "one of the first ones available".

    The SE would be a bit different if it were a pre-release, usually not having the product name on the front, the case would be smooth and shiny.
     
  5. crecords thread starter macrumors newbie

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    tdiaz,

    thank you for your input, either way I hope I made a ok investment. Hopefully I can get them to function. Once I receive them and look inside I will post some pictures if anything looks unusual. Was the hyperdrive unusual on the 512k?
     
  6. tdiaz macrumors 6502

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    Hyperdrive on a 512.. not unusual at all, considering they sold them for exactly that reason. The HyperDrive pre-dates SCSi, though many also used the same mounting hardware and changed to a clip on or sandwich SCSI board for the 512. Between that and stacking RAM, you had the same thing as a Plus.

    When you see a 512 with a ribbon cable hanging out over the floppy port, or with a DB-25 mounted on a plate in place of the battery door.. you know what you've got.

    I don't see the bundle as a horrible deal at that price. Again, it seems like a nice collection from the photos.
     
  7. Anonymous Freak macrumors 601

    Anonymous Freak

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    #7
    Not bad at all for that set up, even if it is all 100% production. (And I'd have to agree, it's almost certain that they are just "production" units bought BY a developer. The fact that the mailing label shows it was shipped to "The Computer Store" (the name of an actual computer store chain in the '80s) rather than directly to either someone's name or the name of a known software developer makes that even more likely.
     
  8. tdiaz macrumors 6502

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    #8
    The HyperDrive, if working .. (well, even if not, but ..) would be nice to get photos of the components and model numbers of the drive and bridge board, for comparison to others.

    Those things were the King of Kludge in their original form.

    I've got a few sets of these disk labels from back in the era .. it was kinda funny, they were serious about backing up. Their drives had a reputation of crashing, too. At Hyper speed... ;-)

    Think about what's going on, with all that stuff shoved into that cabinet, which in later years proved to have a number of heat stress related issues.
     

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  9. crecords thread starter macrumors newbie

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    I will post pictures once I have everything. It's funny I am excited about these old computers. I have never repaired one before but I think I can handle cleaning, a new battery and replacing capacitors if needed. If it goes beyond that I will need help. After a little research it looks like the se would not have much value so I will probably focus on the 512k. I was 13 when this computer came out and could not dream of owning one then. I watched the video of Steve Jobs introducing the macintosh to shareholders, it hits home how important the macintosh was in 1984.
     
  10. tdiaz macrumors 6502

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    #10
    Soldering on the Mac motherboards is a little different than many might be used to, with the multi-layer and power plane inner layers wicking heat.

    If you're removing through hole radial package capacitors on these boards I find it easier break off the capacitor and work on the lead only, because sometimes you may need to do the heat and whack trick to get the solder out, vs. using a bulb sucker.

    As for using solder wick, I'm mixed on that, where you've got boards that tend to easily lift their traces and pads, which certain era Apple boards are, using wick on the surface is like a heat amplifier.

    But I find that just getting most of the solder out means you can wiggle the remaining lead around a little and it can break free.

    But there's the balance of that and making sure you're not peeling out the through-hole plating while doing that either.

    If you've got a vacuum powered unit, you're already ahead of the curve. :)
     
  11. crecords thread starter macrumors newbie

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    Please help me

    I finally received my computers. Here are some pictures of the 512k. I thought I could open it up and take a look but it looks like I would have to take the fan out and the connector where the battery cover should be. Please help me out with this and someone explain what I have. The production number was not that early. Your Macintosh 512 (M0001W), with serial number F4467HSM0001W, was the 8696th manufactured during the 46th week of 1984 in Fremont, CA. It is a shame the box does not match, that serial number was production number 292!
     

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  12. crecords thread starter macrumors newbie

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    I have also found some very interesting disks. Apple Link "for cupertino campus use" macintosh plus version. MacDraw Macproject prerelease versions for demo use only .... one homemade just marked "alice" and microsoft master also along with hyper drive disks
     
  13. tdiaz macrumors 6502

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    #13
    The fan isn't attached to anything on the other side, but wire, as is the SCSI connector over the battery door. The VGA connector is probably a monitor, certainly not VGA, just used as a convenience. They did "strange" things back then.

    The case back still has the same screws in it: Either side of the motherboard, over the battery and two down the handle hole.

    If you've got a case cracker .. otherwise I just do it by pressing on the ports with thumbs while lifting on the sides.

    If it's stuck, putting the unit face down on a couch and "slap and lift" at the same time, at the sides. Slap it in an upward motion, and drop it, do that a few times and then try the port push with thumbs/palms on the case again.

    Since you've got the extra items connected, you'll want to lift slowly, as the SCSI connector will need to be put back through the battery hole, and the other two, disconnected from somewhere.

    Be careful of the neck PCB on the CRT! Knock it, and you can bust the tit on the back of the CRT and .. psssssssssst.
     
  14. crecords thread starter macrumors newbie

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    Getting inside was easier than expected, since it was missing two screws and the fan was unplugged. This was a 512k supercomputer:)
     

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  15. crecords thread starter macrumors newbie

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    forgot to mention there was a AA battery in it, I have the correct battery arriving tomorrow. It would be great if this thing fires up.
     
  16. crecords thread starter macrumors newbie

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    looks like i also need some help finding a cord for the 512k keyboard. I suppose I could order the ends and crimping tool and make one, it would be nice to find an original one though.
     
  17. crecords thread starter macrumors newbie

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    #17
    I found a keyboard cable. I will also mention the jasmine hard drive enclosure has a miniscribe 8425s 20mb hard drive from 1987.
     
  18. tdiaz macrumors 6502

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    #18
    Kinda figured the "HyperDrive" may actually be SCSI, instead of the earlier MFM with a bridge board, just because of the SCSI connector on the back there.

    The keyboard cable -IS NOT WIRED THE SAME AS A PHONE CABLE-

    Do not make that mistake. The keyboard cable is -STRAIGHT- where as the phone handset cable is crossover. Take one end off a phone handset cable and reapply properly.
     
  19. crecords thread starter macrumors newbie

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    #19
    why did the case have the hyperdrive label and just the scsi port? Maybe it had it installed and then removed, explaining the fan??
     
  20. MacTech68, Jan 20, 2014
    Last edited: Jan 20, 2014

    MacTech68 macrumors 68000

    MacTech68

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    #20
    What's the name of this upgrade board? You can almost see it under the floppy cable.

    I'm pretty sure I've fitted one of these years ago, with the VGA video connector in the security port. Wow - memories.

    I'm amazed that the analog board seems to have one of the original flyback transformers, which could indicate it doesn't have upgraded rectifiers on the output of the power supply - a little concerning with all that extra gear.

    If the hard drive works, make a backup of it immediately. Drivers for the upgrades might be hard to come by.
     
  21. tdiaz macrumors 6502

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    #21
    If the drive is "stuck"..

    Maybe some here will cringe and freak out --

    But on MiniScribe, Tandon, Western Digital drives of similar nature, where the stepper motor spindle is accessible from the outside, I just spin it to free the head. In all the years since the 1980's I've never had a problem. If the drive was bad, it was already spinning and doing stupid stuff.

    But if it was stiction, I got the data off it.
     
  22. MacTech68 macrumors 68000

    MacTech68

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    No cringe... done this many times. :)
     
  23. crecords thread starter macrumors newbie

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    I think the external hard drive was used on the mac se that came with this group. That's why I thought it's strange that the 512k has a hyper drive label but no drive in it. The external fires up but I don't have a way to test it yet. I already know the 512k has a checkerboard display and a bad battery. After I clean some corrosion and replace the battery I will turn it on and see what happens next, maybe the capacitors but everything inside looks pretty clean. I did turn the se on and one of the drives is making a clinking sound and no display. I ordered a battery for it too. It has a upgraded video card in it also.
     
  24. tdiaz macrumors 6502

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    It means the HyperDrive went to bit heaven and it was replaced with that SCSI sandwich, and it's fan was just left there in the corner. After being stubborn over the Mac Plus, "well, I have exactly the same thing" .. the SE was probably an upgrade. Perhaps because that 512 crapped out possibly way back then..
     
  25. crecords thread starter macrumors newbie

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    #25
    It works!!

    I received the new battery today and put it in and to my surprise it works!! I have not boot disk but it boots up to the external drive which also works! Could someone tell me how to make a boot disk from the external drive and back it up to a floppy? The floppy works, some of the disks I have work and some dont. I bet the printer works too, we will see.
     

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