Build Your Own PC — Really

There was a time when building your own computer meant a lot of soldering or wire wrapping. At some point, though, building a PC has come to mean buying a motherboard, a power supply, and just plugging a few wires together. There’s nothing wrong with that, but [Scott Baker] wanted to really build a PC. He put together an Xi 8088, a design from [Sergey] who has many interesting projects on his site. [Scott] did a great build log plus a video, which you can see below.

As the name implies, this isn’t a modern i7 powerhouse. It is a classic 8088 PC with a 16-bit backplane. On the plus side, almost everything is conventional through-hole parts, excepting an optional compact flash socket and part of the VGA card. [Scott] acquired the boards from the Retrobrew forum’s inventory of boards where forum users make PCBs available for projects like this.

If you try to duplicate [Scott’s] project, you can learn a few tips from reading his posts. For example, he learned that the resistor SIPs on the CPU board were a bit taller than the IC sockets. The lesson is to install the sockets first.

Scott didn’t use a normal 8088 chip, but rather a NEC V20 which was a common upgrade back in those days. In addition to the backplane and CPU card, [Scott] also built a floppy controller board, a sound card, a compact flash reader, and a VGA board.

There’s a certain amount of cachet to building a PC, even an old-fashioned one. We could be tempted to build one to hook up to some of the old printer port gear we still have hanging around, too.

While the 8088 isn’t a supercomputer, that just means you have to hack harder. Especially if you want to go at 8088 MPH.

37 thoughts on “Build Your Own PC — Really

    1. No RW, it doesn’t

      “Note that the backplane is 16-bit whereas the Xi 8088 CPU card itself is only 8-bit. The Xi 8088 CPU card does have the ability to pass some additional signals on the 16-bit connector. In particular it includes some additional IRQs, as well as MEMW, MEMR, and LA17-LA19.Using a 16-bit backplane also affords the opportunity to use a 16-bit CPU in the future should a 16-bit CPU board ever become available.”

  1. “On the plus side, almost everything is conventional through-hole parts, excepting an optional compact flash socket and part of the VGA card.”

    How is that an advantage? SOIC and 0603 or larger SMD parts are even easier than through-hole.

    1. The *genuine looking* aesthetic is very important to some people. It’s like how a smell can bring back pleasant memories, the DIP aesthetic does the same for some people.

  2. BTW I was somewhat fascinated with backplane based systems back in the day, but never got one working. Only had junk parts picked up from computer fairs. Had one backplane with AT power connection and one 386 module that had io and kbc on plus simm. Could not get a peep out of that, think I tried vga and mono. Found a 286 module later and that didn’t do anything for me either. Not sure if boards were bad pr backplane was, or they were just weirdy parts that needed other proprietary boards to work.

      1. I guessed as much. Internet didn’t have much tech info on at the time, was just what you could gopher and archie and find in newsgroup archives.

        They all got parted with in a move or I’d be interested to try them on this backplane.

  3. Wow, So much DIP! I haven’t see that much DIP since the actual XT!

    Nothing says “I love DIP” quite DIP mounted 7 segment LEDs – cos LEDs fail frequently NOT lol.

    I also love that it fits the card slots of a standard form factor PC case.

    And the OTP DIP switch … love it!

    1. Can be done….
      However problem being all those BGA parts… and then the BIOS/UEFI is something to try to make if intel gives you all the under-NDA documentation.
      Though disintegrating a known brand mainboard and making a custom version of the same configuration, i.e. on-board NVidia-1080Ti by routing the PCIe under it’s BGA instead of a PCI socket. That way you can recycle the BIOS ROM.

      Same with laptops, Got an old cast magnesium-alloy era Inspiron laptop from dell?
      Well get a modern Core i socketed laptop and get a custom PCB made to fit the old shell then solder on the components salvaged from the modern laptop.
      Also because Big-Corp don’t expect such extreme modding, You can give the laptop a MXM slot to spare. Customised batteries will need to be made also to fit old shell.

      .

      Was thinking of getting a custom PCB so I could have the schematics of my dell latitude E6400 inside a metal shell of those old Inspirion, the expense and the risk of getting a track timing wrong…. Became a back of the mind though experiment project… Never got past a 1hour research phase.

        1. Check out bitsavers.org specifically the ‘RecentFiles’ link a ways down the page (also replace /pdf with /bits for most of the binary data going with the documentation. It tends to get mixed up nowadays since they removed the /bits/ RecentFile link and seem to be trying to put everything in the pdf directory instead.) They have technical documents ranging from the Eniac/Univac to late 90s era systems, including the Xerox Altos, 4004 to 80686, iAPX432, etc.

    2. Well, the i7 is a part with 1150 pins. A lot are power, ground, or duplicates, but still a LOT. And then booting a system with a billion transistors. Not for the faint of heart o someone who the time to do something like spend ten years building an airplane – meaning maybe 1500 hours to start.

      1. I give you that. But I would say that when you get to systems with 2-3 chips with kbs of ram, it gets pretty tricky to slip in an unnoticed malware. Especially if os is in rom.

        Today with hundreds of gbs of storage and gbs of ram, it is easy to hide malware. Hardly any single person understands the whole system, while that was possible in the 70-ies.

        1. In the pre IBM XT era you could probably have used a LASER to erase bits through the window of UV EPROM (if LASERs were a common thing) any other method would be much harder.

      2. FDISK /MBR

        I had lots of fun with my boss over that one. He asked where to find information like that and I said there isn’t anywhere – it’s an *undocumented* command.

  4. He should find that the CC error is actually FF but with the damaged drivers causing the bottom of the F from showing. That FF just means no data. 16.5 mins in so far….

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