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IBM 5160 - 301 keyboard error

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    IBM 5160 - 301 keyboard error

    I have a chance to buy IBM 5160 with no keyboard. Seller sent me some pictures and one of them shows 301 error. He said he could not test any further. Is there a way to bypass this error to see if machine will boot. I only have IBM model M keyboard. Also i own compaq portable. Will that keybord work with some kind of adapter?

    Second question: yes. Search on XTAT keyboard adapter. Inexpensive. I will note that some early Model M keyboards could autoswitch, but most can't.


      Thx, I saw an adapter for AT style keyboard
      I did not separate my question enough. I was asking if compaq portable keyboard is compatible with XT protocol. I know it has different connector.


        I'd imagine a portable keyboard would work, but like you said the connector is different. I think you'd be better off just buying a keyboard on ebay that is known to work with an XT class system. I picked up a Keytronic E03600QL-C. It's a decent feeling keyboard, nothing special like a Model M of course, but it works on AT and XT. Mine doesn't have a switch, but there is a hole and imprinted area where some keyboards using that case had switches to go from AT to XT.

        There are also "vintage" keyboards that should work and sometimes are cheaper than a real IBM.

        Keyboards I've got that I've recently tested with an XT are:
        Keytronic KB-5151 (it's weird for an XT class keyboard with only 10 function keys, because they are at the top, not the left side)
        Chicony KB-5160AT (it seems to work on an XT, even though there was an KB-5160XT model too)
        Lite-On SK-8801B-1U (this has a giant XT/AT switch on the bottom. There is one on ebay for like $10 right now. It's a super cheap feeling keyboard though)
        Compaq Enhanced Keyboard

        There is a good possibility the Keytronic and BTC keyboards (and maybe others too) you'll find are foam and foil type switches, that will probably need a lot of help by now, just like your Compaq Portable.


          Some alternatives to the keyboard that IBM supplied with the IBM 5160, are listed at [here].

          ( Lots of IBM 5160 information at )


            Originally posted by Paulk View Post
            I have a chance to buy IBM 5160 with no keyboard. Seller sent me some pictures and one of them shows 301 error. He said he could not test any further. Is there a way to bypass this error to see if machine will boot.
            Yes, it is possible. It is done by putting the power-on self test (POST) of the IBM 5160 motherboard into 'Manufacturing Test' mode. In that mode, one of the consequences is that the check for a keyboard is not done. I confirmed that just now by bringing out an IBM 5160, minus keyboard, and watching the 5160 boot from its hard drive. I then verified that a boot from floppy is possible.

            More information on Manufacturing Test' mode is at [here]. The pointed-to web page includes an example of how to trigger Manufacturing Test mode; by using a DIN plug. Maybe the seller has the means to do that.

            Other possible means of triggering Manufacturing Test mode are:
            - Ground pin 3 on 5160 motherboard chip U85, or;
            - Ground pin 17 on 5160 motherboard chip U27, or;
            - Ground pin 8 on 5160 motherboard chip U68.
            Maybe the seller has the means to do one of those.


              Thx for all advice, i did ground one of the pin in din connector and was able to bypass keyboard error, put floppy disk and machine booted strait to DOS. I decided to buy it. Very exited
              Came with 5151 monitor, 640kb memory, serial and LPT card, real time clock card, 20 mb hard drive. i disconnected hard drive so i can not verify if good, because not sure if need to be park before power down and since i do not have a keyboard.
              Do i need address anything else? Like capacitors?


                Don't worry about the caps until you actually need to. "If it ain't broke, don't fix it" rules.