geekhack
geekhack Community => Keyboards => Topic started by: nowsharing on Mon, 30 March 2009, 22:06:12
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Hi, I'm a casual lurker of your board and am finally making my first post.
I must be searching poorly, because I can't find any discussion of add-on desktop ps2 cards. Is there any reason not to choose a ps2 pci card instead of a usb adaptor? It just seems right to go native...unless these cards use some kind of ps2 to usb process within them anyways. Here (http://cgi.ebay.com/PCI-Low-Profile-Bracket-USB-2-0-Header-Dual-PS2-Card_W0QQitemZ250388734699) is one on ebay that I'm considering. I see that the syba brand ps2 cards have horrid reviews at newegg, so I'm avoiding those. Anyone have experience with this sort of thing?
Cheers
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Are they really PS/2 ports, or PS/2 to USB under the hood?
IIRC, the keyboard and mouse reside on specific interrupts, not necessarily supplied by the PCI bus.
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The PS/2 Ports are compliant with USB HID specification and will work with any PS/2 keyboard or PS/2 mouse.
Seems like they use an internal ps/2 -> usb converter chip.
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I think your best bet is going to be to replace the motherboard with one that has PS/2 connectors for the keyboard and mouse.
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That card may not be a bad idea if you are using a PS/2 keyboard only on one computer (don't need to transport it to another computer that doesn't have PS/2), especially since it looks pretty cheap.
If you end up getting it, let us know how it turns out, especially if you have any problems with any keyboards.
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It's just a PS/2 to USB to PCI adapter...
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Thanks for the insight everyone, it saved me some time and a little cash.
I just read a writeup at ClickyKeyboards on this issue and thought that I should give the definitive end to this question (you can't add native ps2 using these cards), thus killing the hopes of anyone hoping to find a way to add native ps2 to a non-ps2 mobo.
from clickykeyboards.com:
Question: I am very familar with ’puters and am good with a screwdriver and I know how to open my computer. Why can’t I buy an expansion card with a ps/2 port that fits into a PCI slot. I have seen these before on my computers at work and they must be readily available.
A. As a corporate IT admin and systems engineer in real-life, I have seen Dell computers with ps/2 ports on the back of computers where the PCI slot covers are. However, this specialized part sold by Dell (part# F3636) was only intended to be used with certain Dell Optiplex computers. This part does not actually plug into any PCI slots of the motherboard, but insteads uses a 24-pin ribbon cable to connect directly to a special connector on certain Dell Optiplex motherboards.
The keyboard interface is an elementary low-level device and it needs to be initalized very early during the boot process. Any true PC hardware geek with real-world experience knows that the PCI bus is not setup and cannot be used to capture the type of direct, low-level I/O signals between the keyboard and computer.
It's humbling, but there you have it.
The best choice is a ps2 to usb converter (as opposed to just an adapter), there's great info on that here (http://www.clickykeyboards.com/index.cfm/fa/items.main/parentcat/11298/subcatid/0/id/396060). This is probably just a big DUH! for most of you.