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IBM PC AT 5170 BIOS versions

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    Originally posted by pkhoury View Post
    As for the 601 error upon boot, I'm presuming press F1 and the system operates normally?
    I do not remember.

    Originally posted by pkhoury View Post
    It's a shame it's not able to modify the newer BIOS images to not give the 601 error; I'm going to assume part of that is due to the new Type 20 HDD added to the drive table?
    I think the behaviour is either:

    1. Done on purpose; or
    2. A bug introduced when the BIOS authors modified the floppy portion to cater for 720K drives and diskettes; or
    3. A bug introduced when the BIOS authors modified the floppy portion to improve the BIOS.

    With enough effort (investigation + fix), either can be removed. If the behaviour was done on purpose, it may not be wise to remove it. Again, it all 'boils down to' the results of an investigation.


      Hey Everyone,

      Sorry if this is mildly off-topic, but I have a few 5170's I'm working on and I hit a really weird issue. I am trying to use a 128mb DOM IDE module on a 16-bit IDE card with the AMI Bios in a 5170. I was able to make the chips, and it's coming up fine. The module I'm using has a geometry of 492 Cylinders, 16 heads and 32 sectors which is well below the 504mb limit. The machine comes up with this setting, sees the HD, lets me FDISK and format and then, nothing! After playing around some more, I booted from a floppy and go right to the C drive no issue. It will let me create a directory, and copy files from the floppy. I then just tried to run from the root, and then I get a read error. I then noticed, I cannot seem to read anything from the drive no matter what I do! I thought perhaps it was just responding too quickly, and the only other drive I have sitting around is an older 200gb IDE. I set it to 1024-16-63 which is the 504 limit, and I get the exact same behavior. Maybe this drive is too fast too?

      Whatever the case, I'm really perplexed on what else to try short of getting an older HD. I was hoping this setup would work.

      Has anyone seen this, or any suggestions?
      Last edited by Kevin Williams; January 25, 2017, 07:57 AM.


        I've got motherboard of original IBM PC 5170 motherboard (01/10/84) and dumped it by DUMPAT.EXE.

        Then I splited dumped BIOS by using WinHex.

        Now. original BIOS of IBM PC 5170 (01/10/84) is verified perfectly.


          I see all the information says 27256 eproms with 150ns are needed to burn the bios roms. Sources of those chips are a bit sparse. I was looking at the cmos variants "27C256" and wondered if they were compatible such as:


            I found the answer "ROMs can be created by programming 27256 EPROMs or 27C256 EPROMs, ones rated at 150 ns (or faster)." The 27C256 I linked above are compatible. Now to learn how to use this old GTEK 7228 programmer


              IBM PC 5170 BIOS.jpg

              I've got junk of IBM PC 5170 type 1 motherboard.

              This is very early Type 1 release of IBM PC 5170 BIOS.

              Part No. : 6181024 (16KB) + 6181025 (16KB) = 6181028 (32KB) , 6181026 (16KB) + 6181027 (16KB) = 6181029 (32KB)



                Wow! Can we see the entire board please??


                  Originally posted by fs5500 View Post
                  I've got junk of IBM PC 5170 type 1 motherboard.
                  This is very early Type 1 release of IBM PC 5170 BIOS.
                  Part No. : 6181024 (16KB) + 6181025 (16KB) = 6181028 (32KB) , 6181026 (16KB) + 6181027 (16KB) = 6181029 (32KB)
                  Good to see these chips, listed in figure 9 of the document at [here], eventually 'surface'.
                  Because of the 16 KB sized ROM's, we expect shunt block U131 to be in the '27128' position (per [here]).
                  Also expected, are Intel made 8259A interrupt controller chips.
                  Now that we have a photo of the ROM's, I will later add details to [here].



                    Sure, here it is.


                    Thanks very much.
                    Last edited by fs5500; December 5, 2018, 06:33 AM.


                      Thank you!


                        Silly question - could the unpopulated 16 bit connector positions be populated to give the AT 8 16 bit slots instead of just six?


                        Proud owner of 80-0007
               - The only one of its kind.


                          Originally posted by geneb View Post
                          Silly question - could the unpopulated 16 bit connector positions be populated to give the AT 8 16 bit slots instead of just six?
                          You could do that. But it means you cannot use 8-bits cards any more that only fit in a 8-bits slot like the original IBM CGA video card.
                          With kind regards / met vriendelijke groet, Ruud Baltissen



                            @gene . @Ruud

                            I recommend to discuss about non related BIOS topic on another thread.


                              If I want to make an EPROM image, would I just read the image in an EPROM programmer, or is there another way to do it? I haven't checked my system to see what version BIOS I have (5170), but it is a tempest AT (if anyone remembers tempest). TONS of capacitors on the MFM controller and CGA card (which has additional filtering and the RCA outputs removed). Also, EVERY cable, including the power supply, is shielded. The ROMs themselves say Golden Bow up on top. One of the admins on a local vintage group I'm on really wants me to get some ROM dumps.
                              IBM Computers: 5150 (16-64K, 64-256K), 5160, 5161, 5162, 5170 (regular and Tempest), Option 370 16 bit, PC Convertible
                              PS/2 Machines: 30, 40SX, 50Z, 55SX, 60, 70, 77 (Lacuna & Bermuda), 80, 85, 90 XP, 95, "E"
                              Vintage ThinkPads: 300, 360C/CE, 510CS, 560/E, 600E/X, 701C/CS, 700, 720C, 730TE (tablet), 750C/P (color and tablet models), 755C/CE/CD/CDV/CX, 760ED, 765L, 770
                              Vintage UNIX workstations: 2/120, 3/75, 3/60, SS 2/5/20, U2 Ent, HP 715/100, several RS/6000s


                                Originally posted by pkhoury View Post
                                If I want to make an EPROM image, would I just read the image in an EPROM programmer, or is there another way to do it?
                                Try this:


                                or this:

                                PM me if you're looking for 3" or 5" floppy disks. EMail For everything else, Take Another Step