IBM 5160 XT Restoration Project

Discussion in 'Retro & Arcade' started by iMic, Dec 11, 2016.

  1. sonicthemouse

    sonicthemouse Member

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    Thanks, I'll file that away for when the time comes :D

    Nice score!! :leet:

    +1, good info, the feet on my 5150 are in resaonable shape but I could do with some for the various IBM keyboards in my stockpile. Could possibly cut them out of a sheet of cork with a hole saw but the edges wouldn't be as clean :thumbup:
     
  2. OP
    OP
    iMic

    iMic Member

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    I've attached the new feet. Using a rusty but unmodified IBM XT chassis as the reference, I made some cardboard templates to ensure the feet were attached in exactly the right spot, and at the correct distance from each corner. I'll take a picture soon.

    The Microsoft InPort card is installed, and I've run some extra power cabling for the XT-IDE, but the inside of the case is a mess and could still use some tidying.

    And the Seagate ST-412 came out of the machine. The motor needs work, a fresh set of bearings at least which would require a complete disassembly. The gap between the motor and drive casing is filled with dirty grease (a previous attempt to quieten it down), so the motor would need to be stripped out to properly clean it up and address this anyway.

    The difficult decision is whether to disassemble the assembly in an attempt to repair it, considering how rare and expensive these drives are, or whether I should simply sell it on to someone who would keep it as a collectors piece. I'm leaning toward this option, simply because the drive in its current form can be cleaned up and still works, albeit it's noisy at times. Attempting to rebuild it likely wouldn't end well, and another piece of history would end up as scrap. Live and let live, ol' Seagate.


    The upside however is that the MiniScribe 8425 is back in the machine. This drive is a mechanical marvel, with zero defective sectors and a perfect motor assembly after 29 years. It's the original drive from this machine, and it makes those unique seek noises that are so common with MFM drives. It's as happy as a clam, if clams could store data and were IBM compatible. The rotating assembly weighs considerably less, so the bearings are in much better shape, and it draws less power from the IBM's old power supply. Win, win, win.

    The drawback is it still needs some repairs to the wiring (HDD Activity LED) and the fitment inside the case isn't as good as the Seagate. The ST-412 sits flush with the front bezel when mounted, but the MiniScribe sits forward about half a millimetre - or enough to notice a gap. But overall, these issues are minor and easily resolved compared to the issues plaguing the Seagate.


    I'll continue to look for MFM drives and should any come around, I'll likely snap them up so I have something to work with. I still haven't ruled out sourcing a Seagate ST-225 at some point, because it's almost iconic at this point and would look (and sound) excellent in this build.
     
    Last edited: Jun 1, 2017
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  3. azzachaz

    azzachaz Member

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    And this, my friends, is why I love OCAU.

    Good work! keep it up.
     
  4. OP
    OP
    iMic

    iMic Member

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    If I come up with something amusing, I like to throw it in there. :D

    Also, thanks!


    I managed to carefully remove the plastic cap from the underside of the damaged IBM case, and cleaned it up in preparation for installation in the good shell.

    [​IMG]


    The underside of the case is now basically complete, with fresh paint, new feet and the plastic features refitted.

    [​IMG]
     
  5. callan

    callan Member

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    Impressive and thorough work - Props to you:thumbup:

    FWIW we lost a lot of drives in the 80's to bearing failure. Manufacturers just hadn't worked out how to construct, seal and lubricate thrust ball bearings with the necessary tolerances, whilst simultaneously accepting temperature-induced tolerance changes. It wasn't until fluid-dynamic bearings came along that the problem was conclusively solved. They would start with a distinctive "whirr" and then develop "stiction" problems where they would seize when cold - exacerbated by the introduction of teflon coating on drive platters. These would spin out to thicker layers at the edge over time, and the R/W heads would settle into the coating when powered off and parked, and then seize in place.

    Callan
     
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  6. OP
    OP
    iMic

    iMic Member

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    More replacement pieces for the XT:

    [​IMG]


    This ST-412 is whisper quiet and runs beautifully. No surface defects, no bad sectors, and it's cosmetically in great shape. Passed a Surface Scan, Linear and Random Seek Test and Head Positioner Test, both hot and cold. It worked immediately in the XT with the Xebec Rev. 3 controller, but I went ahead and rewrote the low level format anyway to be safe. Installed DOS and the XT's back in business.

    I needed some replacement cables to go with it, although it turns out the cables that came with the drive are different to the ones in the machine, so I'm still using the original XT cables for now.

    Lastly, an AT2XT Keyboard Converter so I can connect any AT or PS/2 standard keyboard to the machine and have it work. Tested, works great with an old DEC keyboard I had sitting around.


    It turns out my machine would have shipped with an IBM 101-key Enhanced Keyboard (Model M) considering mine is a 1986 model, and has the 1986 revision ROM BIOS. Should be easier to source than a Model F, or at least I hope so.

    Now that the machine works, I'm starting to think about what I can do with it. I'd like some networking and sound capabilities in there to open it up a bit, and the rest depends on what software runs on the 8086. There are some IRC clients with XT class compatibility, so I'd like to try connecting it to a network and channel at some point.
     
    Last edited: Oct 14, 2017
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  7. JidaiGeki

    JidaiGeki Member

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    Some nice additions there!

    Not sure how much easier it is to find the 101/102 key 5160 keyboard (http://minuszerodegrees.net/5160/keyboard/5160_keyboard_support.htm suggests 102 keys for non-US) over the 83 key, but here's some pics of what the original setup with the extended keyboard probably looked like (1986 build date on it)

    http://www.nightfallcrew.com/07/08/2013/personal-computer-ibm-5160-monitor-ibm-5151/
     
    Last edited: Oct 14, 2017
  8. Flamin Joe

    Flamin Joe Member

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  9. OP
    OP
    iMic

    iMic Member

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    Picked up some additional toys for the XT:

    • 3Com 8-Bit Ethernet Card with Black Box Transceiver (Coax + RJ45)
    • Netgear 24-Port 10/100 Switch with Coaxial
    • Thin Coax Cable with Terminators

    Which means I should be able to start looking into networking the IBM.

    • Creative Vibra 16S CT2800 Sound Card with Manual I/O and IRQ Jumpers

    With a genuine Yamaha OPL3 chip onboard. Apparently it works in an 8-bit slot, and the manual configuration jumpers may make it usable in the XT as a Sound Blaster or Sound Blaster Pro compatible. It's a temporary solution until I could source a true 8-bit Sound Card, but if it works, it'll do for now.

    • CompactFlash USB Card Reader

    Well, not exactly for the XT, but it does allow me to transfer data to a CompactFlash card, which is then connected to the XT-IDE for fast transfer of software onto the XT's internal hard drive.


    This machine is turning out awesome. I'm looking forward to seeing it on a network, connected to a Telnet BBS, an IRC channel, or playing chiptune music through an internal FM synthesiser. :D

    One issue I need to overcome is how to reattach the rear case labels. These were originally adhesive backed, like a normal sticker, so somehow I need to reapply a fresh layer of peel-and-stick adhesive to the back of them.

    I don't really want to go for the double sided tape or spray adhesive route, because everything in this build so far has been about doing it clean and doing it right, and being so close to completion, I don't want to let that slip now.
     
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  10. badmofo

    badmofo Member

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  11. OP
    OP
    iMic

    iMic Member

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  12. OP
    OP
    iMic

    iMic Member

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    Since the last update, I started assembling the machine and attempting to make all the various components work together. It certainly took some convincing to accept the wide array of cards and accessories being thrown at it. The available IRQs and I/O addresses are almost maxed out, but somehow there were enough free to support all of them at once. There was a minor conflict between the VGA video adapter and the Network Interface as both attempted to communicate on the same IRQ (2/9), but this was resolved by disabling a function of the VGA card otherwise unused on the XT anyway.

    Loading the necessary software and drivers onto the machine was a battle and a half. With a 3.5" Floppy Drive connected to the primary controller temporarily, I was able to format and use 720k disks for the initial transfer with a Windows 98 PC in between as a bridge. This allowed me to install MS-DOS 5, the Sound Blaster Utilities, a Network Packet Driver and the mTCP communication suite onto the internal 10MB drive.

    From there the rest was simple. Connect the Ethernet Transceiver and network cable to an AirPort Express in wireless bridge mode, run the DHCP command to retrieve an IP address, start the XT's FTP server and transfer the remaining data from a MacBook Air wirelessly. Success!

    This IBM XT now communicates online, connecting to IRC channels and Bulletin Board Services (BBS) rather well. Transferring data and classic games around is easy, with the XT FTP server running and an FTP client on a newer machine. With a genuine hardware Yamaha OPL2 FM Synthesiser installed, it produces excellent chiptune music. I'll find some additional instruments and voices for it soon. It even serves static HTML pages - a web server with a 4.77MHz CPU and 640KB RAM.

    [​IMG]


    The machine is almost finished. It needs some minor tweaks, and I'll continue looking for some rare cards and accessories to match it, but I'm pleased with how it's all come together. It's an interesting machine that's surprisingly easy to immerse yourself and get lost in. The fact it communicates so effortlessly with computers 31 years its junior is certainly a plus, and makes it much more usable for specific tasks than some may think it would be.

    Thinking about it for a moment, I'm not convinced I'd be able to perform a restoration of this caliber again. The amount of repair work needed, along with sourcing rare and discontinued parts, turned this into a lengthy and at times expensive process.

    But I don't regret it for a minute, because it's a beautiful machine and one I'm extremely proud of.
     
    Last edited: Dec 19, 2017
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  13. SenatorDC

    SenatorDC New Member

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    Hi not sure if this warrants a new thread. I am looking to get my IBM 5160 operational again. This computer has been with the family since new. 2012 was the last time it was used until 2 weeks ago. From boot I managed to get to the command prompt before hearing a snap pop followed by smoke blowing out the PSU. I've done a tear down and the damage is only to the psu. I think its just the 275v capacitor that went. I've linked a bunch of pics from inside the PSU and want some advice. Actually I'd really appreciate advice! Is it just the capacitor that's gone and would replacing it solve the issue? Could this be a sign of another underlying problem?

    https://photos.app.goo.gl/oyhSYs57ejfvp53R9
     
  14. Flamin Joe

    Flamin Joe Member

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    It's a line filtering cap, they blow all the time in power supplies of this era. It's a symptom of old age as the plastic casing on these film caps become brittle and crack with age allowing moisture to get inside and hasten it's demise.

    I can't remember off the top of my head the capatence rating required but you just need to replace it with a similar rated filter cap (I usually use the Panasonic X2 rated Polyester Film caps) and it should be good to go.

    If you do have any further issues with the system not powering on I'd look at the tantalum caps. They are the next common cause of power on issues on these vintage IBM's.
     
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  15. SenatorDC

    SenatorDC New Member

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    I'll look at ordering the part. I really hope I can fix this myself as I was pretty devastated when this happened. I've looked after the machine well for decades. As you can see in the pic even the PSU is in pretty good nic with little dust.

    Many thanks FJ
     
  16. SenatorDC

    SenatorDC New Member

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  17. Flamin Joe

    Flamin Joe Member

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    Don't stress they are basically a ticking time bomb so it was only a matter of time. Thesedays whenever I see one I just replace it on the spot.

    Yes that looks correct to me. :thumbup:
     
  18. SenatorDC

    SenatorDC New Member

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  19. sean0118

    sean0118 Member

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    I agree it looks correct, but you'll have to pay delivery for Mouser unless your order over $60AUD. RS have the same part with free shipping (if you buy 5):

    https://au.rs-online.com/web/p/polyester-film-capacitors/8697469/

    edit: You'll probably need a new fuse as well? ;)
     
    Last edited: Aug 1, 2019
  20. SenatorDC

    SenatorDC New Member

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    I need a new fuse? Do I need to prevent another issue,? Or is this a reference to my switch box shutting the house down when this one powers up
     
    Last edited: Aug 1, 2019

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