The trackman Marble FX I'm referring to is this one.
Thank you for the clarification. [tips hat]
After seeing the video of Eric S Raymond on the Tech Syndicate youtube channel,
I think I found the video here:
Great stuff. There are some nice lingering shots of a grey-corded, PS/2, T-CL13/Logitech TrackMan Marble+ (the "+" indicates the addition of a scroll wheel) at the 7:38-7:45 mark. I recognised it because I used its white-corded, USB connector successor (the T-BB13) for many years. There were times when I wanted to have a comparatively inexpensive spare on hand for travel and connecting an active PS/2-USB adapter to a T-CL13 effectively gets you a T-BB13, but for less money.
Any road, I am grateful to you for mentioning the video because…well, I’ll see if I can explain.
Yonks ago, Eric S. Raymond wrote this webpage:
http://www.catb.org/esr/trackman-conversion/On it, he talks about how the three-button Trackman T-CL11 is a near-perfect pointing device whose ergonomics are unmatched, then goes on to moan about Logitech adding a scroll wheel, putting a switch in it, and having it serve as a middle button on subsequent Trackman models.
The problem (according to him, at least) is that this change makes possible to accidentally scroll-click when you mean to click. So two button + clickable scroll wheel models are a “deal-killer” (again, according to him). As the page shows, he put a
lot of work into attempting to update his three-button, PS/2 trackball to a USB device.
And now, ages later, I see a video that shows him using… a T-CL13 Trackman with scrollwheel. Interesting - I wonder what prompted him to change his view?
and his logitech thumball, I decided to get one of them for myself. Obviously it had to be an ebay item shipped from the US.
And that's how you ended up with the Logitech M570, is that right?