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Thread: Seeking step-by-step tutorial for (re)flashing BIOS

  1. #1

    Question Seeking step-by-step tutorial for (re)flashing BIOS

    Hello!

    Anticipating a possible upcoming need for (re)flashing BIOSes, I known nothing about it other than:
    • It is an erasable read-only program
    • It resides on a BIOS chip


    Some basic questions (to at least given you an idea of my limited knowledge to start from):

    1. Why is it called flashing?
    2. Is it similar to the modern use of the word "flash memory" as found on USB sticks?
    3. Is there a difference between flashing a BIOS and reflashing a BIOS?
    4. Do you need a special device, or can the BIOS be flashed by somehow accessing the chip via DOS commands, etc.?
    5. If one wants to "load" a BIOS onto the chip, one needs a copy of that BIOS already. Historically, was that BIOS provided to computer buyers on floppy disk?
    6. Can BIOSes of choice (for example, SIIG Enhanced IDE BIOS for SC-JE0012/JE4012/JEE012 version 1.05) be found on any modern website?



    Can someone point to a YouTube video, to a webpage, or explain the step-by-step process of how to (re)flash a BIOS?

  2. #2
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    > It is an erasable read-only program
    > It resides on a BIOS chip

    The BIOS is software that resides on an EEPROM. Electrically Erasable Programmable Read Only Memory.

    > Why is it called flashing?
    Probably a little colloquial. EEPROMS can be updated in a flash of time compared to older UV erased EPROM devices.
    The upgrade software is often called "flash.exe" which re-enforces that nomenclature.

    > Is it similar to the modern use of the word "flash memory" as found on USB sticks?
    Yes. Under the hood it's likely very different (NOR vs NAND) but let's just keep it simple.

    > Is there a difference between flashing a BIOS and reflashing a BIOS?
    Nope. The flash tool first erases the chip (or the portion being written to) and then writes the contents of the file into the freshly erased space. Think of the EEPROM as a chalkboard/whiteboard. Erase the whole thing, then write the message on. You can redo it hundreds or thousands of times.

    > If one wants to "load" a BIOS onto the chip, one needs a copy of that BIOS already. Historically, was that BIOS provided to computer buyers on floppy disk?
    Yes, or via a download from a BBS and now the internet.

    > Can BIOSes of choice (for example, SIIG Enhanced IDE BIOS for SC-JE0012/JE4012/JEE012 version 1.05) be found on any modern website?
    You can likely find anything you want on the internet, but one should be careful to match the flash tool with the BIOS you're going to load with the hardware that the BIOS is going to be running on. A good flash tool will verify a few things before blindly performing the update.

  3. #3
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    Be aware that the chips used to host BIOS code on 'early' motherboards and cards are not 'flashable'; they predate the widespread introduction of flash type memory.
    Common were masked ROM chips and EPROM chips.
    Keeping it simple:

    Masked ROM chip: Cannot be erased nor updated. The chip needs to be replaced with another chip (masked ROM, or possibly EPROM).

    EPROM chip: The EPROM can be removed, erased using an EPROM eraser, and then an EPROM programmer ('burner') device can be used to put new code/data into the EPROM chip.

    More information is at [here].

  4. #4

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    Thanks for the link to that article by Terry. I see he has a lot of useful articles like that.

    Okay, so assuming for the moment that I have all the information needed to do the operation (the knowledge of all steps and how to do them properly, and a copy of the desired BIOS), I still need the minimum hardware of an EPROM eraser and an EPROM programmer/writer.

    Shoot. Nothing's ever easy with vintage computers when you're learning it the first time.

    Well, what are good websites to find BIOSes on to download, such as the one I gave above, SIIG Enhanced IDE BIOS for SC-JE0012/JE4012/JEE012 version 1.05?

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    Quote Originally Posted by Bill-kun View Post
    Thanks for the link to that article by Terry. I see he has a lot of useful articles like that.
    Some additional info at [here].

    Quote Originally Posted by Bill-kun View Post
    Okay, so assuming for the moment that I have all the information needed to do the operation (the knowledge of all steps and how to do them properly, and a copy of the desired BIOS), I still need the minimum hardware of an EPROM eraser and an EPROM programmer/writer.
    Or, some of the people/companies at [here] can do it for you.

    Quote Originally Posted by Bill-kun View Post
    Well, what are good websites to find BIOSes on to download, such as the one I gave above, SIIG Enhanced IDE BIOS for SC-JE0012/JE4012/JEE012 version 1.05?
    You may be hoping to hear something like, "Try site xxx for BIOS'. The hit rate is over 90%." I doubt that such a site exists. Copies of BIOS' (if available) are scattered. For example, I have some on my web page at [here]. For example, some are here at the VCF, deposited within posts. If I am looking for something, I just do an Internet search, and hope. Some BIOS' may be on a copy of the maker's web site that web.archive.org archived. You can make a request at these forums, and see what eventuates.

    Note that some BIOS' have requirements. For example, people who have the ROM-less version of the SCSI card shown at [here], wanting to fit a BIOS ROM, need to fit a PAL chip in addition to the BIOS ROM. For example, some BIOS upgrades to cards may require that the card meet a certain minimum hardware revision. For another example, see post 3 at [here].

  6. #6

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    I don't know if I will reflash the BIOS as I said. This is all anticipatory learning as I am troubleshooting other issues.

    Nevertheless, I have found massive resources for BIOS images, and am putting the links here for myself or anyone else in the future.

    VOGONS Vintage Driver Library > Motherboards > BIOS Images
    http://www.vogonsdrivers.com/index.p...enustate=30,29

    BIOS Image Collection, forum post by user Predator99, with links to BIOS images for for XT; 80286; 80386; 80486; Socket 4, 5, 7; and EGA video cards
    https://www.vogons.org/viewtopic.php?t=60356

  7. #7
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    For what computer is this going to be done? Why do you need to flash the BIOS? Is there a known issue that is solved by an updated BIOS? Are trying to use an updated BIOS from the OEM or some BIOS found on the web? Lastly, I would not try to erase and update the original chip if you are not 100.00000% sure you are going to be successful with creating a new working BIOS. I will suggest a second EPROM of the correct type is cheap insurance if you don't wish to end up with a door stop since you can at least go back to using the original BIOS chip.
    Crazy old guy with a basement full of Pentium 1 laptops and parts

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    You should be careful in any case. I had a Tandberg SLR drive and flashed the wrong firmware, essentially bricking the unit. Worse, the EEPROM PLCC was soldered in. I eventually rescued the drive by unsoldering the EEPROM, soldering in a new SMT PLCC socket, then reflashing the EEPROM with the correct firmware, back into the drive and all was well.

    "Bricking" motherboards by flashing the wrong firmware in any case is particularly well-known. More modern motherboards have a protected "boot block" that can help to restore the system to operation.

  9. #9
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    In the age of CP/M computer and such you needed an EPROM programmer to program a PROM, EPROM or EEPROM with a monitor program (not called a BIOS since that was part of CP/M) that often was written in assembly code and modified by the user. By the 90's often an updated BIOS was provided by the OEM as a .BIN file and used a version of Flash.com to program the BIOS chip on the motherboard. This often required loading the Flash program plus the .BIN file on a new floppy disk and insert the disk into the drive and powering the computer up. If all went well and power didn't go out after what seemed like forever the programing would finish without any "done" message. So you waited 30 minutes or more just to be safe and then pulled the diskette out of the drive and rebooted the computer. Hopefully the BIOS was updated and Bob was your uncle. Way too often you had a boat anchor, door stop or brick.

    More modern computer as stated above have recovery circuitry that at least allows you to try again if not just return to the original BIOS.

    Since early computers were all different from each other there were no aftermarket BIOS files that were generic to multiple computers. Only since IBM PC's has anyone attempted make special "try this, you'll like it" BIOS files.

    I know one laptop maker that supplied updated BIOS files that 99.99% of the time lead to a door stop and since the chip was soldered to the motherboard was a real PITA to recover from a user attempting to do their own updates.

    I still have dozens of .BIN files for early laptops and before I had my own EPROM programmer used to pull the BIOS chip out of a running computer and plug in a second chip in and program it on the fly. Not for the weak at heart and the results were worth it because I had a source of spare motherboards. Not something to DIY at home kids.

    Modern BIOS programming is about as simple as instructions for a can of soup. "Open can before heating" But you can't make something fool proof, fools are just too ingenious and keep coming up with new ways to screw something up.
    Last edited by DeltaDon; November 27th, 2020 at 10:19 AM.
    Crazy old guy with a basement full of Pentium 1 laptops and parts

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