On Wed, Aug 17, 2011 at 2:17 PM, <meino.cra...@gmx.de> wrote: > Paul Hartman <paul.hartman+gen...@gmail.com> [11-08-17 21:08]: >> On Wed, Aug 17, 2011 at 1:42 PM, <meino.cra...@gmx.de> wrote: >> > Paul Hartman <paul.hartman+gen...@gmail.com> [11-08-17 18:02]: >> >> On Tue, Aug 16, 2011 at 10:01 PM, <meino.cra...@gmx.de> wrote: >> >> > Hi, >> >> > >> >> > I have attached an old keyboard (PS/2-connector) via an >> >> > USB-PS/2-adaptor to my PC. >> >> > >> >> > When typing too fast (...) the three LEDs of the keyboard flashes >> >> > and everything typed then is typed as if the CTRL-Key constantly >> >> > locked (I am using the X-window-system with openbox as windowmanager. >> >> > There is no session management.) >> >> > >> >> > It is possible to revert back to normal when I switch >> >> > from X-windows to the Linux console (CTRL-ALT-F1) and back >> >> > to X (CTRL-ALT-F7). >> >> > >> >> > My question is: >> >> > What part (PC? Adapator? Keyboard?) gets out of sync here is >> >> > "resetted" (somehow), while switching between console and >> >> > X-windows? >> >> > >> >> > How can I reset the behaviour without switching? How can I >> >> > prevent the behaviour completly? >> >> >> >> FWIW I have experienced that same behavior with several PS/2 to USB >> >> adapters, in Windows, in Linux, etc. I think it's a common problem >> >> with those adapters in general. I've never used one that didn't "go >> >> crazy" a few times a day. >> >> >> > Hi Paul, >> > >> > after some recursive investigations :) via internet I found some >> > interesting things: >> > 1) Yes, your are completly right: It is the USB-PS2-adapter, which >> > goes crazy. >> > 2) No, you are wrong, the reason is different. >> > ;) :) >> > 3) The answer is 41.999998 (calculated by a P90). ;) >> > >> > The reason for stuck CTRL/SHIFT keys is a missing pull-up >> > resistor from the clock and the data line to the +5V line >> > of the PS2 connection. Or in other words: Adding these resistors >> > seem to fix the problem in most cases. >> > See the link below (which describes the process for a IBM Model M >> > keyboard. Seems true >> > for other old PS2 keyboards as mine, too): >> > http://ps-2.kev009.com:8081/ohlandl/keyboard/modify_keyboard/Model_M_Modifications.html >> > >> > The PS2 goes crazy because the high level gets too low without the >> > additonal pull up resistors. But the "origin of the reason" is not >> > the adapter, but the low high levels of the old PS2 line as such. >> > >> > I did find these information that late (after posting to this list) >> > by searching for informations about certain different usb-PS/2-adapter. >> > Sorry, when answering the other half of my own question.... :) >> >> Very interesting info, it's good to know the real reason why it always >> seems like a "universal" problem with those adapters. >> >> In the end, to solve my own problem, I bought two Unicomp keyboards >> which are the same as the old heavy IBM keyboards but with USB >> built-in. ;) >> > > (my question is based only on curiosity...) > > Are the Unicomp Model Ms of the same quality and tactile/audible > feeling as the original IBM model Ms?
Yes, in fact it's exactly the same. Unicomp was formed by former IBM/Lexmark employees who bought the original Model M manufacturing equipment and rights to the original designs and parts from IBM. So it's very much the same as Model M but available with updated with modern features like USB and windows keys (if desired) and different colors. They are still manufactured in the US at Unicomp's offices and not outsourced to China or anywhere like that. USD $80 seems like a lot of money for a keyboard to some people I talk to, who are used to getting the crap $5 rubber keyboard from the computer store. :) but if you spend every day typing, like I do, it's really a small amount to pay. I've been using mine for a few years now and am extremely happy with them. I have the original huge one (the "Customizer") and the smaller one with a trackpoint mouse in the middle (it's smaller but still heavy and clicky, using the same spring mechanism as the big guy).
