Planning - PS/2 switch

[InSanCen]

So, I want to have an "Otaku" M13 board to accelerate learning touch-typing, and am ordering the caps from Unicomp in a week or two. The problem with that is my Other Half says no on the grounds that she does not touch-type, and my Daughter is just learning to use a keyboard. Fair enough.

My solution? Make an A/B switch, and use both the "Otaku" M13 and another board.

All I need is conformation that I'm not going to screw up my motherboard. I don't plan on switching the 5v lines at all (I plan on powering from an external PSU to the switch box, with both boards +v lines active, running only the data lines to the PS/2 port on the motherboard). I do plan on switching the data lines. I think that a simple SPDT switch on the data lines should sort things out nicely. Maybe a debounce if needed to smooth the switchover.

Assuming there are no problems, and if there is call, I'll post a schematic, BoM, and pictures. It should, in theory, be a very simple device, using a box, 2 female, 1 male 6 pin mini-DIN ports, a SPDT switch, 6 core shielded cable, and some Veroboard. It will need a few more components if debounce is needed.

Can anyone see any glaring problems with this?

[ripster]

Don't mess with power line and it should be fine but still may require a reboot.

Two Blue Cube or Belkin USB dongles with a Ikea magazine tray bolted to your table would be more elegant IMHO.

http://www.instructables.com/id/Stylish ... heap-Maga/

[captain]

Why not just use a proper keyboard switch? I have one that goes the other way: 4 computers can't be switched to one monitor and keyboard/mouse set.

[Maarten]

Switching PS/2 devices on the fly should be possible if they are similar enough hardware-wise. However, i would do kinda what Ripster suggested but instead of 2 blue cubes i would just hook the most used keyboard up via PS/2 (or whoever needs NKRO roll-over the most, dunno if your little girl happens to be a hardcore Korean gamer in the making or not) and the other by USB. This will only set you back a couple of bucks, no messy rewiring necessary and will be pretty much guaranteed to work out of the box.

[InSanCen]

Ripster - I don't need storage space for the boards, but I do need 2 to be ready to go, and I have room on my desk for this. However, I don't want both "active" at the same time. If it doesn't pan out, this is what I plan on doing.

Captain - I'm not sure a pre-made PS/2 switch exists, or at least exists in a form that I can buy easily and affordably.

Maarten - No Korean gamers, or anyone who needs NKRO at all (although the little one does love Minecraft). My other half prefers the AT102W, I love my M13, my Daughter has yet to express a preference, and this is the only reason for what I am planning.

It won't cost much to try it out, and I like tinkering and building things. I'll post back on the success, or otherwise, of the box. If it does work, I wonder if I can make a soft-touch box with a momentary button, rather than a hard switch...

[kbdfr]

[[...] I'm not sure a pre-made PS/2 switch exists, or at least exists in a form that I can buy easily and affordably.

This is the same I use every day without any problems to connect (and even interconnect) several Tipro keyboards:
http://www.ebay.com/itm/230664777098

And this is a similar one for just connecting two keyboards to a computer:
http://www.ebay.com/itm/300427787996

[captain]

Those links are exactly what I was talking about. Ripster's idea is really he best though. What does it matter if both keyboards are live? Only one will be in use at a time, and you can cover up the other one if you fear keyboard cat or something.

[InSanCen]

Cheers for the links. I never thought to look for a "data transfer switch".

I've just bought the parts today... and they cost more than the whole unit.

Oh well, I guess I'll build it anyway, and see if it works. It will do as a backup if nothing else.

[graboy]

I read over that a few times because I didn't quite get it on the first, and maybe I don't, still, but how is this different from a KVM switch? Seems like a much easier alternative.

[Maarten]

KVM- One keyboard, one mouse, one monitor and up to many many computers
OP- Multiple keyboards, one PC.

Its the exact opposite.

[kbdfr]

KVM- One keyboard, one mouse, one monitor and up to many many computers
OP- Multiple keyboards, one PC.

Its the exact opposite.

Mechanical ones like those quoted in my previous post work both ways:

This is the same I use every day without any problems to connect (and even interconnect) several Tipro keyboards:
http://www.ebay.com/itm/230664777098

And this is a similar one for just connecting two keyboards to a computer:
http://www.ebay.com/itm/300427787996

[Maarten]

Some can do that yes but not all, the reverse capability is simply not a standard feature on KVMs (just like how some can also switch USB, audio and networking features). So saying that somone should just go out and buy any KVM switch would be wrong.

[kbdfr]

Of course not any KVM.
Mechanical switches just internally connect wires.
It's just like unplugging from one socket and plugging into another socket, no electronics involved.

[InSanCen]

KVM's are also more expensive than a simple switch, regardless of the ability, or lack of, to switch multiple keyboards on one PC.