ps/2 keyboard to usb adapter, how to make - Electronic Circuits Projects Diagrams Free

bd13 · 6th October 2004, 08:26 PM

i think the title says it all, so anyone know how to do this??

heres what i know: usb cable/port has 4 pins, a v+, a ground, and two data wires. a ps/2 keyboard port has 5 pins, a v+, a ground, a data wire, and a clock wire, and one pin is not in use-or as they said on that one site- "not implemented". considering many things, the top one being that the adapters for a mouse+keyboard to usb cost 20$ i would like to make my own. i come to this after a couple of conclusions: looking at the item in stores and this picture on ebay (only keyboard to usb)

it seems to me there is little to no room at all to put an IC, or any type of uncommon electronic part, and because there is a 4 to 4 pin match up with the two ports i have come to the conclusion that it would be easy to make my own adapter (i have a usb cable and a ps/2 keybaord) i know to match up the V+ and ground wires but i have no clue how to hook up the other two wires. anyone know how.

**Nigel Goodwin** · 6th October 2004, 09:51 PM

They don't match up!, USB and PS2 keyboard are totally different things. However, some devices may include the hardware and software for both PS2 and USB (I have mice that do this), but a standard PS2 only keyboard won't interface to a USB port with a simple lead - neither the hardware or software is compatible.

bd13 · 6th October 2004, 11:01 PM

then why do the adapters work?

**Nigel Goodwin** · 7th October 2004, 08:52 AM

Quote:

Originally Posted by bd13

then why do the adapters work?

If an adaptor works, with a PS2 ONLY device, it must have electronics inside to convert between the two formats - which is why it costs $20.

6th October 2004, 08:26 PM	(permalink)
bd13 Experienced Member	ps/2 keyboard to usb adapter, how to make i think the title says it all, so anyone know how to do this?? heres what i know: usb cable/port has 4 pins, a v+, a ground, and two data wires. a ps/2 keyboard port has 5 pins, a v+, a ground, a data wire, and a clock wire, and one pin is not in use-or as they said on that one site- "not implemented". considering many things, the top one being that the adapters for a mouse+keyboard to usb cost 20$ i would like to make my own. i come to this after a couple of conclusions: looking at the item in stores and this picture on ebay (only keyboard to usb) it seems to me there is little to no room at all to put an IC, or any type of uncommon electronic part, and because there is a 4 to 4 pin match up with the two ports i have come to the conclusion that it would be easy to make my own adapter (i have a usb cable and a ps/2 keybaord) i know to match up the V+ and ground wires but i have no clue how to hook up the other two wires. anyone know how. __________________ w00t!

6th October 2004, 09:51 PM	(permalink)
Nigel Goodwin Super Moderator	They don't match up!, USB and PS2 keyboard are totally different things. However, some devices may include the hardware and software for both PS2 and USB (I have mice that do this), but a standard PS2 only keyboard won't interface to a USB port with a simple lead - neither the hardware or software is compatible. __________________ PIC programmer software, and PIC Tutorials at: http://www.winpicprog.co.uk

6th October 2004, 11:01 PM	(permalink)
bd13 Experienced Member	then why do the adapters work? __________________ w00t!

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