nowhere in the ad does it say it's bolt modded. don't be misled, guys!
The bolt modded is the one sold by Bro Caps, not the ebay one - I asked because Bro Caps post mentioned it.
That is my bad, I had to shuffle some posts around.
Why do you say the SSK is 2KRO? Is that something peculiar to SSKs or is it true of Model Ms in general? I always thought the PS/2 connector was superior to USB in that it allows more rollover combinations - but does the Model M not take advantage of that?
The SSK has a membrane as the actual keyborad matrix and is 2KRO like almost all membrane keyboards.
I recommend reading this page about kb matrix circuits
http://www.dribin.org/dave/keyboard/one_html/Basically, there's only continuity (or lack thereof) between the nodes, and no place for diodes (or something exotic, like the microsoft sidewinder kb uses)
PS/2 has the bandwidth to support NKRO for keyboards, whereas "full speed" USB 1.1 only supports 6 key and a few modifers. USB 2.0 supports enough for NKRO, but isn't common in keyboards.
so for a KB to have NKRO, it has to have an NKRO compatible circuit, an NKRO compatible controller, and use an NKRO compatible protocol. The SSK only has the latter. Many USB keyboards have the first two. My current keyboard (IBM F 122 with soarer's converter) has all three.
hope this helps.