Path: utzoo!news-server.csri.toronto.edu!cs.utexas.edu!sdd.hp.com!zaphod.mps.ohio-state.edu!ub!acsu.buffalo.edu From: jones@acsu.buffalo.edu (terry a jones) Newsgroups: comp.sys.ibm.pc.hardware Subject: Re: KEYBOARD problem Message-ID: <63042@eerie.acsu.Buffalo.EDU> Date: 4 Mar 91 15:08:28 GMT References: <38652@netnews.upenn.edu> Sender: news@acsu.Buffalo.EDU Organization: SUNY Buffalo Lines: 48 Nntp-Posting-Host: beatrix.eng.buffalo.edu In article <38652@netnews.upenn.edu> awhite@eniac.seas.upenn.edu (Andrew J. White) writes: >I have an intermittent problem with my keyboard when I physically >turn my computer on. About half the time everything is fine, but >the other half the time the keyboard does not work. I get a keyboard >error, the num/caps/scroll lock lights blink very rapidly, and my >PC makes the same noise as when the keyboard type-ahead buffer is >full and you keep pressing keys. > >I have tried another keyboard and experienced no problems; I conclude >the problem is my keyboard. It is a fairly new Mitsumi 101-key enhanced >keyboard. Anyone know what causes this and how I might fix it, short >of replacing the keyboard? It is possible that your new keyboard is coming out of reset too soon for your system on powerup. In this condition, the keyboard handshaking that occurs when you apply power to the system does not complete. Where the keyboard initiates the handshake before the keyboard controller on the motherboard is ready to negotiate. The keyboard gives up the ghost while the controller on the motherboard begins listening for the handshake that will never happen. I've had this problem with a couple of system/keyboard combos. Generally what I do is to put a larger cap in the reset generation circuitry for the keyboard's controller. This holds the keyboard in reset longer when power is applied, and things are happy. Note that I do this in the keyboard itself, I don't recommend you muck with the motherboard too much. But then again, you may not be comfortable with the concept of hacking in your keyboard either. Oddly enough, you can see if this is the problem by disconnecting the keyboard from the system prior to powering it up. Once the system is going, plug the keyboard in, and it should work. Again, this is not the greatest thing to do since it is theoretically possible to ping something by plugging peripherals in while the system is powered up. I've had no problem doing this, but I'd rather you made the call.... I'd try calling for some tech support on the keyboard first. If that goes nowhere, and you really like the keyboard and want to fix it...mail me and I can help you out if you need it. Good luck -- Terry Jones {rutgers,uunet}!acsu.buffalo.edu!jones SUNY at Buffalo ECE Dept. or: rutgers!ub!jones You are in a maze of twisty little compiler features, all different.