geekhack

geekhack Community => Keyboards => Topic started by: wellington1869 on Fri, 17 October 2008, 14:03:55

Title: Chaining AT-PS2 adapter to ps2-USB -- any issues?
Post by: wellington1869 on Fri, 17 October 2008, 14:03:55

Hi guys,

I'm considering buying an old clicky (blue cherry) qtronix scorpius KT-305 keyboard that has an AT connector. My computer only takes USB. Any known issues with chaining an AT-PS2 adapter followed by PS2-USB adapter? (the latter is a 'real' one, not just a pass thru).
If it makes any difference, i have winxp.
thanks!

Title: Chaining AT-PS2 adapter to ps2-USB -- any issues?
Post by: itlnstln on Fri, 17 October 2008, 20:48:29

I think several people here already do that.  Since AT and PS2 are the same protocol, all you are only doing one protocol change.  Some folks would probably agree with this; if you have the option to run with PS2, do it.  It has better throughput/bandwidth (?) so it allows for higher key rollover.  USB can only support 6-key rollover, PS2 can handle much more.  That is not to say USB is unusable.  I probably never run into a situation where I need 6-key rollover.  I have also heard stories of less-than-successful adapting from PS2 to USB as well (I have never run into this personally; I run PS2 to USB from my Model M through a KVM switch with no problems).

Title: Chaining AT-PS2 adapter to ps2-USB -- any issues?
Post by: lowpoly on Sat, 18 October 2008, 13:56:18

The passive just-a-cable PS/2 to USB converters do not work well.

Title: Chaining AT-PS2 adapter to ps2-USB -- any issues?
Post by: bhtooefr on Sat, 18 October 2008, 13:59:16

Also, some active PS/2-to-USB adapters don't play nicely with Model Ms, due to the Model M's power consumption.

Title: Chaining AT-PS2 adapter to ps2-USB -- any issues?
Post by: itlnstln on Sat, 18 October 2008, 20:31:11

I have this one from monoprice.com: http://www.monoprice.com/products/product.asp?c_id=104&cp_id=10404&cs_id=1040401&p_id=173&seq=1&format=2.  It's $4, and it works great with my Model M.  Every one in a while (maybe twice a day) the keyboard acts like it resets.  It lasts less than one second, but I don't know if that is the adapter or the switch (or both).  It happens very rarely, so I don't really care.