1) The keyboard works flawlessly with my DTK 286 system. This is the original system it came with, and my first computer (my father bought it in 1988). The keyboard has an AT connector.
2) I use a KVM switch to use the keyboard on my multiple retro systems. The KVM switch is PS2/analog VGA. So the keyboard is connected through AT to PS2 adapter into the switch, then from PS2 to AT onto the 286. Works.
3) Second computer connected was an Intel Pentium 2 with intel 440BX board. Keyboard -> PS2 KVM -> PS2 i440BX - works a treat.
Now for the problems. My "newest" retro system is Duron 1200mhz, Ati Rage Fury MAXX etc. Board is aOpen AK73. When connected to PS2 port, there is no way the keyboard works. Ever. Upon startup, the 3 lights blink, but that's all. I've fiddled with various BIOS settings, to no avail.
I read somewhere that 'modern' PS/2 ports do not deliver enough power for these old keyboards. Okay, so I bought a "blue cube" [after a little research] active PS/2 to USB adapter. Exactly this item: http://www.ebay.com/itm/351291284423
The adapter arrived. Keyboard is not working with Duron PC. Again, only LEDs light up briefly, then it's dead. I said OK, let's try my macbook air. Nothing. A "keyboard identification wizard" pops up, but that's as far as you can go. No keypress is ever registered. The wizard pops up even with an unplugged PS/2 connection into the adapter. That means the blue cube adapter is idetifying itself as an USB keyboard in all cases (good), but it does not pick up anything from my K104 plugged into it. Why?
Can the keyboard draw be any more than USB current limit, let's say 2.5W (5V / 0.5A) on my macbook air? Why does the keyboard work on an intel i440bx and not on the duron?
I'm confused by this. Being a noob into keyboards, I just now read on this forum the function of the switch on the back of the keyboard. Could this be the case? Should I flick the switch?
Attaching some pictures of my keyboard. What switches are those? Are those really that valuable as stated in f-o-r-s-a-l-e-f58/monterey-k104-montere ... 10175.html or is that just a troll thread?
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Keyboard history: If you don't care, please skip!
I just want to share how I got this keyboard and this 286. This was actually my first computer back in ~1996 when I was 8 years old. My father bought it in 1988. It comes with the original monitor, and this keyboard. It has a SAMPO graphics adapter, with VGA output. 1MB RAM, 40MB MFM harddrive, still works. The system was 'lost' in ~1996 when we upgraded, later I found out my father gave it to a family member, who had 'thrown' it into an apartment that she owned, but never used. Then she moved abroad and the whole thing was forgotten. In 2013, she visited us and told us that she is selling the apartment, and asked us if we want it. I went on an tour. It was a dusty, reminescent of the past and forgotten apartment. And then, on the table was my old 286!
) How happy I was, I asked if I can keep it, and she was like of course, I don't need it! Nice, so I took it home, disassembled it fully, thoroughly cleaned, replaced the leaky CMOS battery, inspected the power supply, and disassembled and cleaned the keyboard as well. And she works! Later I started my 'vintage PC' workbench.I didn't really pay any attention to the keyboard, after a good clean, it works great, so I realised I should use this keyboard for my retro PC bench. It wasn't until today I found all the comments about 'blue switches' when researching the USB connection problem. Could it be that the keyboard is really rare? Please let me know. No plans on selling it though, cause it works really nice, and I don't mind playing some old games on it.
Also, the fact that I can toggle numlock in XT mode without any problems, means that power for the keyboard should be sufficient (at least I hope so! 
