On 12/9/2018 5:24 PM, Paul wrote:
wrote:
On Sun, 09 Dec 2018 15:26:48 -0500, Paul
wrote:

wrote:
On Sun, 9 Dec 2018 11:39:39 -0500, John McGaw wrote:

On 12/9/2018 10:43 AM, wrote:
I am trying to fire up this W7 PC to eventually use on a PS/2 KVM. The
PC has only one PS/2 connection (plus a few USBs of course).Â*Â* I want
to use a keyboard and a mouse which both are PS/2.Â* I tried using both
the keyboard and mouse one at a time and both work during bootup. So
they both seem to work.Â*Â*Â* Even in W7 altho stillÂ* only one at a time.
I have to make things work with both mouse and keyboard connect of
course.Â*Â* I then tried using both connected to a Y connector which
changes the connections to the single PC USB input connection.Â* Both
mouse and keyboard still work during boot.Â* However, when I get to W7,
neither work.Â* Funny, since both work when alone. Even when using the
Y connector.Â* So the mouse, keyboard, Y connector, and PC USB port all
seem to be good individually, but not together, which I seem to need.

aarrrggghhhhh!

???

I hope someone can tell me what to try.
Al

No guarantees:

https://www.amazon.com/StarTech-Keyb...dp/B000067SLZ/


There are cheaper alternatives availlble.

That looks like mine except the white end on my 'y' is USB.Â* Are you
saying that reducing the keyboard and mouse PS/2 connectors down to
one PC/2 connector will work when mine won't?Â* That wud mean the
problem is in the conversion from PS/2 to USB wouldn't it?
Al
There are two adapters.

John is showing your the PS/2 splitter. It's passive and
just a rewiring job in effect. The PS/2 on your PC, has
enough wires on it to run two connectors... if that's how
they wired it on the motherboard. If the motherboard end
isn't the right type, the PS/2 splitter only works on
one port. The mouse CLK/DATA are wired to one connector,
the keyboard CLK/DATA are wired to the second connector.
Power and GND are wired as you would expect.

Â*Â* PS/2 (6 pins) -------- PS/2 4 pins get wired as normal
Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â* \________ PS/2 4 pins get wired as normal

There is a tiny reference in the comments of the pinout diagram
here. It tells you how the motherboard end can be using all
six pins, to house two interface sets.

https://en.wikipedia.org/wiki/PS/2_port

Â*Â* Pin 1Â*Â*Â*Â* +DATAÂ*Â*Â*Â*Â* Data
Â*Â* Pin 2Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â* Not connected [b]
Â*Â* Pin 3Â*Â*Â*Â*Â* GNDÂ*Â*Â*Â*Â*Â* Ground
Â*Â* Pin 4Â*Â*Â*Â*Â* VccÂ*Â*Â*Â*Â*Â* +5 V DC at 275 mA
Â*Â* Pin 5Â*Â*Â*Â* +CLKÂ*Â*Â*Â*Â*Â* Clock
Â*Â* Pin 6Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â* Not connected [c]

Â*Â* [b]Â* Sometimes, keyboard Data for splitter cable
Â*Â* [c]Â* Sometimes, keyboard Clock for splitter cable

*******

The other kind of adapter for PCs, is an active adapter
that converts a USB port to two PS/2 ports.

Â*Â*Â* USB ------- 8 bit micro ----------- PS/2 mouse
Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â* inside plasticÂ*Â* ------ PS/2 keyboard
Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â* blob

Those rely on a fixed firmware the 8 bit micro runs,
to convert PS/2 serial protocol, into USB packets.
Usually on the order of $10 to $12 or so. At one point,
that micro went out of production, so it's hard to say
which chip they use today.

Â*Â* Paul

Thanks for your input.Â* I have researched PS/2 to USB converters and
have been scared away.Â* I wanted to use my ATEN CS-114A KVM which is
PS/2 for my multiple PCs but they lack PS/2 ports.Â* I had thought
converting PS/2 to USB would be simple, but I guess not.Â* What to do
what to do.

Al

If you have the bi-color green/purple PS/2 connector on
the motherboard end, try the passive "PS/2 to two PS/2" adapter.
Like John suggested.

Throwing the active USB to dual PS/2 into the mix,
with a KVM, is just asking for trouble, since you'll
be attempting to send in-band hotkey combinations,
and those little active adapters might present an issue.
The active adapter is an "unknown quantity" in any
case, as you're relying on the firmware to do just
the right thing, with any possible keyboard input.
There's no way to know how good of a job they did.

Since the PS/2 to dual PS/2 adapter is passive,
there are no more "conversions" in the path, than is
normal. Those adapters are just wires, no chips.

If the passive adapter doesn't work, you're out $10.
And the active adapter at that point, looks no more
of a positive than before. It would still be
another $10 crap-shoot. If you have the bi-colored
PS/2, I'd try the passive. (I really like PS/2,
because it's always worked for me. It has a track
record that is hard to match with the more high
tech stuff.)

Â*Â* Paul

Probably cheaper than that. There were several other similar adapters on
Amazon for fewer $. I simply listed the one I did because, for some reason
or another, I've had good luck with various StarTech cables and adapters
and it has good-ish ratings. Probably all of these things them come out of
the same Chinese factory.