geekhack
geekhack Community => Keyboards => Topic started by: wellington1869 on Tue, 02 December 2008, 12:57:16
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So I'm trying out my new model M (1391401, ps2). I have a ps2 to usb adapter on it which has worked well with other ps2 boards in the past. I have it plugged directly into my laptop (not thru a hub).
What I'm seeing is missed characters and ghost characters. It will type fine for a sentence or so and then will suddenly, for example, wont type an "S" for about 10 seconds. If I keep trying, it eventually does, and then its normal again for a sentence or two.
Ghost characters - sometimes it will type characters that I havent pressed. again only now and then while being normal in between. And sometimes it will print lots of spaces when I hit the spacebar just once - and then go back to normal for another few minutes.
If I keep typing, it generally behaves, and I can sometimes go half a page or more before any issues appear.
Is this an issue with my ps2-usb adapter? Or does it sound like a keyboard issue to you?
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Has the adapter worked on other Model M's or just other ps2 boards?
Clickykeyboards has some information on this issue and which adapters to use. The M uses much more juice, if I remember correctly, than more modern boards and only a few adapters actually work...something about some adapters being only adapters, and others being signal converter?
Anyway check out the site...
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well, its worked with other ps2 boards, havent tried it before with a model M.
Problem is I dont know if this is a voltage/current issue (and thus if the 18 buck adapter from clickykeyboards will fix it) or if this is a more basic keyboard problem...
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One thing I've noticed - if I type for a long period of time, the missing/ghosting character problem becomes very rare.
If I stop for 2 minutes and resume, the problems immediately return.
If I keep at it and type a long document, the problems once again pretty much go away (until next time I stop).
Does that say its a current/voltage supply issue?
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The only way to find out is to find a ps2 port...if the issue doesn't persist, I'd recommend the another adapter.
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The only way to find out is to find a ps2 port...if the issue doesn't persist, I'd recommend the another adapter.
alright, I'll haul it into work tomorrow. I think we have a couple of old desktops with ps2 ports. If the problem doesnt appear immediately there too, then I guess its an adapter issue. I hope thats all it is, I really like the 'board!
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I tried various PS/2 to USB adapters with my Unicomp (with Windows keys) and never found one that worked reliably. Even those little square cubes like what clickykeyboards.com used to recommend didn't work. At best it would work most of the time and then drop keys or get a stuck key. Other adapters would drop something like 30% of key presses. A used a Belkin adapter for a bit and I'd say that it was probably the most usable out of the lot.
Having said that, the Unicomp works differently to my IBM UK board. The Unicomp for example doesn't suffer from issues with pressing the cursor keys along with certain alpha keys (e.g. when playing racing games or GTA) whereas the IBM board blocks certain combinations. So perhaps there is something different about Unicomp and IBM boards that makes the recommended adapter not work. But that isn't relevant to your problem.
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If you have the option, I would just use PS2.
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If you have the option, I would just use PS2.
well, I just tried it in ps2 and it came up as "keyboard failure"! Tried it on a couple of diff machines with same result. Contacted seller about replacement...
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You didn't stick in the mouse port, did you? Also, does your BIOS have you choose between PS2 and USB? You may want to check that, too.
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You didn't stick in the mouse port, did you? Also, does your BIOS have you choose between PS2 and USB? You may want to check that, too.
well these desktops were already using a dell ps2 keyboard, so I shut down both machines, removed the dell ps2 board, plugged in the model m, then booted. On both machines it flashed "keyboard failure". (I also waited till it booted up all the way, opened up notepad and tried typing on both, no response). I turned off both again, plugged the dell ps2 board back in, booted, and both worked fine again.
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clickykeyboards.com mentions that the Model M often needs more power than is normal over the usb hub. They sell one specific adapter that they know works. So if you are having problems with an M over USB, best first step is to test it on a PS2 port and if its good, buy the adapter from clickykeyboards.
Since yours isn't good on multiple ps/2 ports, swapping it is the best bet.
First thing I would test would be the cable, it would be great if you could test with a known good cable.
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First thing I would test would be the cable, it would be great if you could test with a known good cable.
wish I had one... anyway I believe he's sending me another. Hopefully I'll be able to keep this one for parts :)
I must say I love the switches :)
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You didn't stick in the mouse port, did you?
oh, to answer your question, I dont think so. It was the purple port (not the green one). IIRC purple is for the keyb on these dell machines. Anyway it was the same port that I yanked the dell board out of...
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If anyone is looking for the same PS/2-USB adapter that Clickykeyboards sells, this one on Amazon appears to be the same one, for $6.99:
http://www.amazon.com/PS2-Keyboard-To-USB-Adapter/dp/B000BSJFJS
I haven't tried any of the adapters and am trying to stick with PS/2, which these days slightly limits which motherboards I can buy. :(
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If anyone is looking for the same PS/2-USB adapter that Clickykeyboards sells, this one on Amazon appears to be the same one, for $6.99:
http://www.amazon.com/PS2-Keyboard-To-USB-Adapter/dp/B000BSJFJS
I haven't tried any of the adapters and am trying to stick with PS/2, which these days slightly limits which motherboards I can buy. :(
it does look very similar, I wonder if its the same. I guess there's one way to find out ;)
This old post (see the last few lines) (http://geekhack.org/showpost.php?p=1502&postcount=6) seems to indicate others have used the cheaper ziotek at amazon successfully with model M boards.
Thanks for that link, Qwerty. I didnt realize it was avail on amaz for so much less. Definitely good to know :)
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I bought this ps/2 to usb adapter (http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&ssPageName=STRK:MEWNX:IT&item=300276332064) on eBay a few days ago, and while it works pretty much ok with the Model M Mini I've tested, it has a weird problem: it "blocks" the key found in Euro boards between the "left shift" and the "Z" key.
Nothing happens when you press that key - I've also tried with a Dell AT102w and it exhibits the same behaviour. Got another ps/2 to usb adapter from Vivanco (http://www.microdirect.co.uk/(18358)Vivanco-PS2-USB-Keyboard---And-Mouse-Adaptor.aspx) that works correctly though (except that after some months of usage the keyboard port is dead and the mouse port now works as a keyboard port....:confused:).
I don't know if it's my item which is defective or it's a design flaw of this model, just watch out if you want to buy one like this and use it with an Euro board (as this model seems the most commonly found on eBay from different sellers).
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These (http://www.shoppalstores.com/ibmmodelm/image//modelm_usb-001.jpg) actually work quite well with Model M's. I bought mine a while back from ClickyKeyboards, but they can be had for cheaper elsewhere.
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These (http://www.shoppalstores.com/ibmmodelm/image//modelm_usb-001.jpg) actually work quite well with Model M's. I bought mine a while back from ClickyKeyboards, but they can be had for cheaper elsewhere.
I have one of these too, aside from being large it has worked well for me.
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When I can, I also like to use the non-adapter. This adapter mitigates potential problems by simply not existing. When in place, it allows the keyboard to perform based on its original intended use, and allows the 'board utiilize all of the original functionality. The best part, of course, is that it's free, and, due to its infinitesimally small form-factor, it reduces annoying cable clutter. Get yours today!
/Billy Mays
/D*ck
/Smart-A*s
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I bought this ps/2 to usb adapter (http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&ssPageName=STRK:MEWNX:IT&item=300276332064) on eBay a few days ago, and while it works pretty much ok with the Model M Mini I've tested, it has a weird problem: it "blocks" the key found in Euro boards between the "left shift" and the "Z" key.
I have a similar looking adapter to that, and it has the same problem with the back-slash key not working. For me too it worked superbly apart from that issue, but it made it useless for me and I was never able to find a solution. There appear to be other PS/2 to USB adapters that suffer from the same problem, but they can be reprogrammed via a command sequence entered via the connected keyboard.
These (http://www.shoppalstores.com/ibmmodelm/image//modelm_usb-001.jpg) actually work quite well with Model M's. I bought mine a while back from ClickyKeyboards, but they can be had for cheaper elsewhere.
Those are the ones that don't work for me - lots of dropped key-presses on my Unicomp Customizer 105.
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I have a similar looking adapter to that, and it has the same problem with the back-slash key not working. For me too it worked superbly apart from that issue, but it made it useless for me and I was never able to find a solution. There appear to be other PS/2 to USB adapters that suffer from the same problem, but they can be reprogrammed via a command sequence entered via the connected keyboard.
Those are the ones that don't work for me - lots of dropped key-presses on my Unicomp Customizer 105.
It might be that the Unicomps have a different controller than the original Model Ms, thus causing them not to work as well with the adapter.
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It might be that the Unicomps have a different controller than the original Model Ms, thus causing them not to work as well with the adapter.
it sounds like people need a small collection of these adapters to make sure they have something in hand that works with all their boards.
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The one I linked to earlier from Monoprice has worked with a variety of keyboards even over a KVM switch. I would suggest starting there, and collecting others at Monoprice since they are so cheap there.
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clickykeyboards.com mentions that the Model M often needs more power than is normal over the usb hub.
I would try the mod (http://www.geocities.com/jszybowski/keyboard/index.htm) they linked to if you can, it's only two resistors tapping the +5v to supply the Clock and Data lines. This is well under 500mA, which is (according to Windows) the max current per port on all of the USB hubs I've tried.
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I would try the mod (http://www.geocities.com/jszybowski/keyboard/index.htm) they linked to if you can, it's only two resistors tapping the +5v to supply the Clock and Data lines. This is well under 500mA, which is (according to Windows) the max current per port on all of the USB hubs I've tried.
ya the mod looks straightforward enough; unfortunately it was even simpler to pay $10 for the ziotek adapter at amazon ;) Which I think will solve the problem for now...
When I eventually try to construct my dream M board though I'll whip out the old soldering gun and do things like this ;)
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I have a similar looking adapter to that, and it has the same problem with the back-slash key not working. For me too it worked superbly apart from that issue, but it made it useless for me and I was never able to find a solution. There appear to be other PS/2 to USB adapters that suffer from the same problem, but they can be reprogrammed via a command sequence entered via the connected keyboard.
Bummer. You'd think an UK-based seller would sell adapters compatible with the UK layout at least.
Do you have more information about that command sequence, to see if it has any effect on it?