And this is the Cherry KXN3-8451 infrared keyboard

introduced in 1984 at a price of 275 US dollars.

And yes, this is a wireless mechanical keyboard from the mid 80s and it's awesome.

This was meant not only as a replacement to the IBM PCjr’s infamously awful keyboard

from 1983, which originally came with this gummy chiclet abomination and even later on

came with one of these, which was better yet still not ideal.

But it was also sold as a wireless alternative to the IBM PC and XT’s 83-key Model F keyboard.

So what do you get with this Cherry board if you're replacing that wonderful thing?

Well to start with these key caps are double shot matte finish ones.

They're also cast in a shape that makes them a little bit shorter and lower profile than

IBM's keys, so while your fingers won’t be bouncing up and down quite as much they

still feel comfortable and they're laid out in such a way that anyone used to an IBM PC

keyboard of the time will feel pretty much at home.

Speaking of layout, this is not the traditional 83-key IBM PC keyboard, but instead this has 84 keys.

And I admire the way that they advertised it as having an “enhanced layout with shift

in the proper position, a horizontal return key, and an extra return key.”

And you know, I'm inclined to agree with them.

I personally do prefer a horizontal return key as opposed to the vertical one on the

Model F, and the shift on the left hand side of the keyboard is indeed at the proper position,

and that extra return over on the numpad is where the 84th key comes in: a handy thing

indeed for the numpad-addicted.

As for underneath the keys, well, this is where the mechanical stuff happens.

These are Cherry MX Blacks, or rather some early variant of them that were introduced

the same years this keyboard in 1984.

And as you can see from this Cherry advertisement of the same year

there were several different types available.

But the ones on here are linear switches.

There is no tactile or audible click, and they’re somewhat stiff, taking about 75

grams of force to press down.

Now that could just be due to the age and condition of these particular switches since

they're supposed to be only 62 grams, according to Cherry.

Either way, 1984 MX Blacks, pretty good stuff!

And in case you're wondering about the spacebar, yes it does take more force to press down

as you might expect at a little over 80 grams in this case.

But, unlike later boards with MX Blacks installed, this does not use a linear grey switch underneath

the space bar.

Instead it's another MX Black, just with a splotch of red paint,

presumably to indicate it's for the space bar.

And inside of that is a slightly stiffer spring.

Now, one thing I'm always looking for in mechanical boards is N-key rollover, which refers to

the limit or lack of limit for simultaneous key presses.

And according to Cherry's ad for this board ot boasts “pseudo N-key rollover.”

I don't know exactly what they mean in this exact context, I've seen some companies that

say that and they're actually referencing 18-key rollover.

But regardless it is not a full NKRO keyboard so there is

some kind of limit here for simultaneous key presses.

And being that it's a wireless board let's check out the battery situation, and this

takes four double-a batteries in this removable tray underneath.

And the company seemed quite proud of what they pulled off here with their quote “state-of-the-art

CMOS electronic components and special circuitry” that would only draw power when a key is pressed,

extending battery life up to 1 million keystrokes.

Around the rear of the unit you'll see these little circular things here, these are the

infrared ports which will transmit to a PCjr, and it is indeed compatible with the jr’s

integrated infrared receiver.

But it also included a cord to plug in the back of the machine for wired usage.

And these cords with the RJ-11 on one end and the PCjr connection on the other are really

hard to find nowadays so I'm happy this came with it.

However, to use this on a PC/XT or compatible you just flip this switch underneath

from “junior” to “senior.”

[chuckles] There's officially no such thing as a “PC Senior,” but they just called

it that anyway and I think it's cute.

And to get it working with the “senior” you'll also need the optional Cherry 0B99-13AL

interface, which provides you both an infrared receiver and a converter for the PCjr keyboard

cable to plug it into the 5-pin DIN connection of the PC/XT keyboard port.

Now It was Cherry's claim that the wireless mode would function at up to 20 feet at an

angle of up to 50 degrees, providing you have complete line of sight

and no electrical or optical interference.

And well, I've had problems with interference and infrared keyboards before.

Like I used to use CFL light bulbs to light my scenes and when I did a review of the original

PCjr version of King's Quest that caused all sorts of problems.

[incessant beeping when lights are turned on] “Yeah.”

[beeping continues!]

To counteract this a bit the receiver box also has this switch on the bottom to choose

between high and low modes, which reduces the reception range and in turn reduces the

potential for outside interference.

And finally you also get two manuals with the full package here: one for the PCjr-compatible

keyboard and one for the PC interface box.

These not only provide some excellent technical information but plenty of troubleshooting

tips for when things inevitably go weird with the infrared side of the equation.

Pretty much if things are beeping like crazy, you've done something wrong and it's gonna need fixin’.

Yeah, let's go ahead and hook this thing up and give it a try.

I have got a PCjr and a PC “senior” at the ready, so let's get to it!

[disk drive goes brank] “Brank!”

All right, so I've got the PC junior turned on here and batteries in the Cherry infrared

keyboard, and well, moment of truth!

That is the infrared receiver built into this thing and of course it

has its own transmitting so [types] Haha!

Yeah, that works perfectly fine it seems even right up close, which is good.

Definitely don't have a N-key rollover.

It's not even accepting that at all, at least not on the PCjr.

But... [typing sounds] we can run a classy BASIC program.

Let's try something else here.

Ooh, I don't know if it caught it.

Nooo.

There we go.

[loud but lovely floppy disk drive noises]

And you gotta love the sound of that disk drive.

Okay.

So uh, yeah.

We can do DOS things.

All right, so we know that it works.

Another thing I want to test is the distance, and remember Cherry said that this would work

at a distance of up to 20 feet with no interference.

I don't actually have a room in my house that is 20 feet long, but I can get pretty close to that.

I'm walking, let’s see, about 15 feet?

This might be about 20 feet.

I am all the way two rooms away, through a couple of doorways through the hallway.

[typing sounds] And it appears to be working.

I can't actually see from here -- I mean, I can see from here but it's just blurry even

with glasses because eyesight.

[type type] And yeah, there we go!

I see the disk reading in there.

Man, yeah that absolutely seems to work without a hitch!

And I've got all sorts of lights and objects in the way

and a camera and tripod were in the line of sight.

So this is pretty darn impressive, seems to do everything Cherry said that it would!

And just to verify what I already know but maybe someone's curious.

Yes, the cable that it came with does work with the original PC junior rather unfortunate

chiclet keyboard right here, as well as the updated PC junior keyboard with the slightly

nicer keys and mechanism.

But still nowhere near the mechanical goodness of the Cherry keyboard.

But yeah, you can kind of see here actually, as far as the key shape and everything, what

they were really going for with the Cherry.

Of course the mechanism you get here isn't nearly as nice as what you get on the Cherry

board, it's just that little rubber dome with the membrane underneath.

But that's definitely the feel overall that they were going for with the Cherry board.

And speaking of this once again let's head on over

to an IBM PC/XT and see how it works with that!

All right, so now I have it plugged into the PC “Senior XT,” I guess they would call it.

And to start with I'm just going to try it in the wired mode, with the box just plugged

in directly to the computer and then that plugged in directly to this, and then we'll

try it wireless afterward.

At the moment though I just want to see if indeed it works and it seems to.

I just wanted to see if it converted over correctly to this XT and I mean, you know,

so far so good.

Typing seems just fine fine.

[more typing sounds]

I missed a space there, but yeah that space is seriously heavy.

Okay, I assume we're going to turn the computer off in order to get the wireless enabled.

[PC powers on]

Alright no beeping so far that's good.

Hmm.

That's not doing anything from right here.

Sensitivity is on high, not that it necessarily needs it, being this close.

I'm assuming that it's just the angle.

Heh, yep.

[chuckles, types]

Oh good.

Let's see where [presses keys] yeah.

If the sensor is up there I'm I really should put the sensor off to the side to get this to...

[grunts, moves things]

Okay.

Haha!

It still doesn't -- you have to like -- oh my goodness.

I need a way bigger desk!

[shuffling things]

Will this work?

That works.

[type-y type type]

Yeah, great.

So with my limited desk space I had to move the computer over here, put the IR receiver

over there, put the legs down and then this!

This works, that's about as close as I can get the keyboard and still have it pick up.

And granted I mean, it's working pretty great at this point.

This is fine.

Well, let's do something on here, got BurgerTime.

[game intro music plays on PC speaker]

[more PC speaker, keyboard sounds]

Oh, dear.

Okay.

[happy BurgerTime PC speaker sounds]

Yay, BurgerTime!

Yeah, anyway, the keyboard it's fine, works fine.

Let's try one other thing because I was told that I could.

Yeah man.

So that's pretty much it for this keyboard!

It's a vintage mechanical, better than some of the alternatives that were around back then.

But honestly there were so many really well made keyboards at the time and it's just like,

this is just one of them.

The thing that really makes this special is of course it's an early Cherry.

And the fact that it's, you know, PC “Senior” and PC junior compatible is just a lot of fun.

I don't have any other keyboards like that.

Kamikaze mission!

Come on guys, there we go haha!

Anyway, ah yeah.

That's pretty much it for this episode of LGR!

I hope that you enjoyed a look at a keyboard of all things,

I mean it’s just a keyboard, right?

But honestly, I like “just keyboards!”

Especially when they have some sort of unique attributes, whether they be an early version

of something that is now a bit more iconic like a Cherry MX switch, or it's wireless

and compatible with multiple systems, or it's just a well-built keyboard.

I might cover some more in the future if you liked this, either way though I had fun and

I hope that you did too.

Feel free to check out some of my other videos on vintage computer-y things right here, there

are new videos of all kinds every Monday and Friday on LGR.

And as always, thank you very much for watching!