IBM PC AT 5170 Rev. 1 BIOS Upgrade (supporting 1.44MB FDD)?

If I'm planning on buying an IBM PC AT 5170 that has the Rev. 1, would it be possible to update the BIOS that'll support the 1.44MB FDD? I'd like to know how that'll work. I did update the BIOS on my Packard Bell Pack-Mate 28 Plus, but the system took a while to turn on since it uses an external battery that's hooked up to the 4-pin jumper on the motherboard, and I'm planning on installing a CR2032 battery holder as the clock battery.


  • Do you have a ROM programmer?

    All that needs to happen is two new chips need to programmed with the replacement BIOS version and then swapping the old chips with the new chips. Don't throw away your old chips until you are sure the new ROMs work. covers the concept in more detail.

  • edited February 2018

    If you update to the final version of the BIOS then you will be able to select a 1.4mb floppy disk type using a setup program. You might be able to locate some genuine ROM chips, or you may program your own with EPROMs. If you don’t have an EPROM programmer, someone in your area might be able to help out.

    If you are replacing the ROMs, you may also consider upgrading to a third party BIOS (Award, AMI or Quadtel). These will give you a built-in ROM setup program, and support for user-defined hard drive types. Personally, that is what I would recommend.

    There is more information about the IBM bios revisions, and BIOS downloads here:

    Another alternative to add a 1.44mb is using an 8-bit XT high density floppy controller card that provides its own BIOS.

    If you don’t need the ability to boot, you can install without the BIOS support and load a device driver at startup.

    Edit: oops didn't see menage's post. Oh well.

  • edited February 2018

    Motherboard types are different between 1 and 2-3.

    According to modem7, there seems to be no problem to use 1.44MB floppy drive.

    This is just like upgrading (or replacing) BIOS as foillows.

    1) IBM PC 5150 Rev.1/Rev.2 BIOS (with 16-64KB board) --> Rev.3
    2) IBM PC 5170 Rev.0/Rev.1 BIOS (with 64-256KB board) --> Rev.2 or Rev.3

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