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Thread: My 8086 Deskpro is on its last legs.....Upgrade time!

  1. #1

    Default My 8086 Deskpro is on its last legs.....Upgrade time!

    My 8086 Deskpro has been acting flakey and has a few issues.

    Last night I powered on and it popped a tantalum capacitor, not the first one so that by itself is not a big deal or hard to fix but it has been giving me issues for the past couple of years.

    Has a dead ISA slot and one that sometimes works and sometimes does not.

    It's at the point that I sometimes dread turning it on because of the ol "well what next will go wrong".

    Current Specs: 8086 Compaq Deskpro 8086

    V30 CPU
    8087 co-processor.
    640k of ram
    2mb Rampage card
    3Com 903 8 bit eithernet card
    XTIDE V1, bought as a kit and assembled it years ago.
    Logitech bus mouse card
    Microsoft bus mouse
    Original Amber monitor and dual mode video card
    16 bit MFM controller card that lets me use a 1.44 mb floppy and the original 360K floppy drive.
    212 MB IDE hard drive.

    First off I am not looking to add a X570 motherboard/3700X cpu/ 64 Gigs of ram/GTX2080 to it.

    I already have tons of Pc's from a generic 8088 to a few Dual and Quad cpu Xeon servers, a couple of 486's, Pentium 75, 100, 133, K6, K6-2, Pentium 3, Athlon 64, Phenom 2 and on and on......come to think of it I really have too much crap but i'm single LOL.

    I love that pc, been having it for decades so I want to keep the "feel" of it but get rid of the unreliability, I want to keep the feel and sounds its been having for decades.

    I'm not interested in gaming on it so really no graphic intensive programs at all, mostly just text stuff.

    So what to do?

    I found a NOS motherboard, but i'm worried about the reliability of it.

    Thought about a Deskpro 286 motherboard swap, then a 386 Deskpro board swap.... the 286 board would be just as old and the 386 is almost as old and has its own issues with the that design.

    I want to keep Compaq DOS 3.31 and 5.0 when I feel the need to swap hard drives.

    I want to be able to plug in the original MFM 20 MB hard drive from time to time.

    I love the Amber monitor.

    Keyboard is ok, i'm used to it.

    Keep the bus mouse.

    So I'm defiantly thinking of swapping out to a newer motherboard but new enough to be more reliable but still has only ISA slots, as I want to be able to use my isa cards, and hopefully with a cr2032, or a separate battery holder not a barrel battery.

    Yes the power supply is non AT standard, also the motherboard is defiantly not standard either.

    The power supply, I have three or four spares including one thats dead that i'm thinking I can easily mount a AT supply in it since its big enough and I could wire it to use the original power switch.

    ATA motherboard mounting is defiantly doable.

    So i'm thinking of a newer 386 or 486 board, only ISA no PCI slots, slow 386 or 486 with turbo and cache off at all times.

    4 MB at most of ram.

    Reuse the XTide card, bus mouse card, network card, occasionally use the MFM hard drive, I have both 8 and 16 bit controller cards, amber monitor I only ever used it on the higher resolution so a replacement video card that will drive it at the higher res is would I would want, I do not think the dual mode card would work correctly but I would give it a shot to see.

    What about the keyboard connector? Deskpros that I have seen come with either a plastic one soldered on the motherboard at the front of the motherboard, or like mine a five pin header and a connector thats bolted to the case. Thats a easy fix as I can remove the replacement board keyboard and solder a jumper harness directly to the motherboard and run it to the original keyboard connector on the front of the case.

    Also I have seen a 486 motherboard with a 5 pin keyboard header in almost the same spot as the original 8086 board.

    So I guess I really need just to find the right motherboard, yes I know there were upgrade boards to retrofit the early deskpros to faster cpu's but I have only seen them in ads but they are old and weird too.

    Any suggestions on a board?

    Yea I also realize any 386 or 486 board I find is old also but at least they will be a few years newer and maybe give the old Deskpro a few more years of life.
    Last edited by Klee; March 10th, 2020 at 04:49 PM. Reason: cuz I needed to

  2. #2

    Default

    couple of pics:





    Original board compared to a tiny 486 board, the round stand offs could easily be re positioned for a standard ATA pattern.

  3. #3

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    I have a Deskpro 286 (same case configuration as the original Deskpro) with a dead MB and also looked for replacement MBs. Nothing came close. The way the drive cage is arranged and the openings for the slots just doesn't match anything else. Not to mention the power supply differences. Best to try a replacement Compaq MB. A 286 would give you a performance boost, but I like the nonstandard configuration of the 8086 (I have two).

    Edit after seeing Klee's pics. I guess I have a MB to search for...

  4. #4

    Default

    See the round stand off's? They are held on by one rivet and one tab, so they could be moved where needed and new holes drilled and either rivets or short screws. Or even maybe just epoxied in place.

    The only real issue is the tab at the rear of the case near the monitor connector is where one of the two screw that holds the original motherboard in would need to be bent down, also I would need to get creative where the motherboard standoffs at the rear of the board by the isa slots would need to be.

    The power supply's are massive, could be easily gutted and a newer smaller at supply could be mounted inside.

  5. #5

    Default

    A generic 8088 motherboard.




    Pic from a few years ago, sure has yellowed a bit since then.

    Last edited by Klee; March 10th, 2020 at 06:15 PM.

  6. #6
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    Default

    Get rid of that barrel battery on the 386 board or you're going to have a bad time.

  7. #7

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    A 286 or 386 is just too fast for that keyboard And depending on BIOS, may not like it. My Deskpros are very similarly configured to yours (except I haven't found a network card to work with it). To me it really hits a nice performance mark - not painfully slow like a 4.77 MHz 8088, but not too fast to mess up that early '80s retro vibe. Even my Deskpro 386/25 is too fast when only 16 bit goodness is desired. So, yeah, my vote is for a NOS 8086 MB.

  8. #8

    Default

    Too late, I already gambled and ordered a 486 board off ebay.

    I have used regular XT keyboards with my deskpro, I also have one keyboard with alot of sticking keys that has a at/xt switch on it, will have to take it apart to see whats in it.

    Made a lowball offer and the seller took it, was not expecting that. LOL

    Has a 486 sx on a unusual package, maybe a Intel Underdrive cpu? LOL





    Has a keyboard header in the right place.



    Its one of those spur of the moment purchases and I used money I already had in my payapl account, I may or may not regret it. LOL

    Seems to be in excellent shape, will test it out in as regular at case before I even attempt to mod the Deskpro case.
    Last edited by Klee; March 10th, 2020 at 08:19 PM.

  9. #9

    Default

    Quote Originally Posted by GiGaBiTe View Post
    Get rid of that barrel battery on the 386 board or you're going to have a bad time.

    That board has been dead for years, just using it for fitment purposes.

  10. #10

    Default

    I cleaned the ISA slots on the original 8086 motherboard, cut out the exploded capacitor and put it back together.

    The dead slot is now working, one of the four molex connector ports on the motherboard is dead now but the other three still work.

    So the Deskpro 8086 is working again.

    Doing a Checkit pro quick test right now just to stress it a little.

    I need to familiarize my self with it again, don't remember what software I had installed but I at least its working again as it was.

    Mtcp needs to be updated, still running the version from 2013.

    When I get the 486 board i'll put it in a AT case and test it out and then decide what to do.

    I also have a newer version XT-IDE card to install, been wanting to put the V1 card in my 8088 generic pc for a while now.

    So things are undecided for now as what direction I will end up going, just depends on the 486 board being good and if it looks like it can be mounted and/or the 8086 board working ok.
    Last edited by Klee; March 12th, 2020 at 07:47 PM.

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