Old Costar keyboard.

[asdfghjkl]

I recently was given an old costar keyboard but I don't know if it works at all.

Here's some pics




It's a/x switch is broken and I don't have any dim to PS/2 adapters.
What would be the first thing to do so I can find out if it works?

[Hak Foo]

Be delicate.  Omron switches are pretty rare, so they might be desirable for someone who just wants to try them,

Possibility-- you could jumper where the AT/XT switch was to be permanently in AT position, assuning you're running on a 286 or higher.

[rootwyrm]

Be delicate.  Omron switches are pretty rare, so they might be desirable for someone who just wants to try them,

Possibility-- you could jumper where the AT/XT switch was to be permanently in AT position, assuning you're running on a 286 or higher.

You can jumper the XT/AT switch with a wire easily. If you get me some shots of the PCB I can tell you exactly how to do it, too. The switch in most implementations switches between firmware loads, by connecting two different pins on the controller.

Unfortunately, I have some serious concerns about the plate - that bubbling is rust. Very, very bad rust. Right at the stabilizer area, too. And rust repair would require completely disassembling right down to a full desolder, plus you're going to need to bathe the PCB, plus sand and repaint the plate. Which may not be sufficient depending how deep the rot goes - if it's just surface rust, POR-15 does the job fine. If it's deeper through, that means having to replace the whole plate. The whole thing. You must replace all the rusted screws, but that's the easy part - they're just standard screws you can get at Home Depot.

And oh gods yes, be very careful with the switches. They are extremely rare and basically impossible to replace.

[asdfghjkl]

Be delicate.  Omron switches are pretty rare, so they might be desirable for someone who just wants to try them,

Possibility-- you could jumper where the AT/XT switch was to be permanently in AT position, assuning you're running on a 286 or higher.

You can jumper the XT/AT switch with a wire easily. If you get me some shots of the PCB I can tell you exactly how to do it, too. The switch in most implementations switches between firmware loads, by connecting two different pins on the controller.

Unfortunately, I have some serious concerns about the plate - that bubbling is rust. Very, very bad rust. Right at the stabilizer area, too. And rust repair would require completely disassembling right down to a full desolder, plus you're going to need to bathe the PCB, plus sand and repaint the plate. Which may not be sufficient depending how deep the rot goes - if it's just surface rust, POR-15 does the job fine. If it's deeper through, that means having to replace the whole plate. The whole thing. You must replace all the rusted screws, but that's the easy part - they're just standard screws you can get at Home Depot.

And oh gods yes, be very careful with the switches. They are extremely rare and basically impossible to replace.

Its surface rust thankfuly, I'm going to try putting power through it soon.

[Reomero]

I didn't know Omron switches for keyboards existed... I only knew about the microswitches found in mice.

What do they feel like?

[asdfghjkl]

I didn't know Omron switches for keyboards existed... I only knew about the microswitches found in mice.

What do they feel like?

There very tactile and quite loud

[asdfghjkl]

It surface rust but is quite allot


The 2 wires from the at/xt switch

[asdfghjkl]

OK caps lock, scroll lock and number lock all work with 5v power input that's a good sign

Time to start fixing the rust and yellowing

[rootwyrm]

Yep, that's the controller style I was expecting - XT/AT is a firmware load switch. You just need to determine which side is the OPEN one. The XT position is probably the open (No Connection) position and AT is likely closed. But you need to test. Which yes, literally consists of connecting the wires together. Just make sure it's a solid connection (butt joint or terminal screw) because "flipping the switch" while the controller's hot can fry the controller.

[asdfghjkl]

Xt is open at is closed