PS/2 and USB Keyboard Converters Chosen by Signal Direction
Identify which side is the computer and which side is the keyboard before choosing an active converter or passive adapter.
We have not performed hands-on testing of the products discussed. Manufacturer references and official guidance support the documented information below; comparison exercises are our editorial guidance.
A PS/2-to-USB purchase is easy to reverse accidentally because product titles often mention both interfaces. The practical question is whether an older PS/2 keyboard must connect to a USB computer or a USB keyboard must connect to a PS/2 system. Those are different conversion directions, and a small passive plug adapter is not automatically a universal protocol converter.
Draw the actual direction
Write computer interface on one side and peripheral interface on the other. Include mouse requirements separately if both devices must be converted. The StarTech examples describe opposite directions, illustrating why similar connector colours and a shared brand do not establish equivalent functions.
Check whether the keyboard or mouse itself documents support for a passive adapter. Some peripheral designs may support more than one interface, but that must be established for the exact model. An active converter handles a defined protocol conversion; a passive connector arrangement does not create that ability in an arbitrary device. Avoid selecting from connector fit alone.
Verify supported features and system use
Identify whether the setup is an ordinary computer, a KVM or another legacy device. Special keyboard keys, mouse functions and pre-boot operation can have separate support requirements. Ask the converter maker about the exact intended arrangement rather than assuming a successful desktop connection proves every BIOS or KVM function will work.
For example, retaining an old PS/2 keyboard on a modern USB desktop is a different task from using a USB keyboard with an older PS/2 KVM. A converter suitable for the first may be the wrong direction for the second. Keep the required keyboard and mouse roles clear so a dual-connector product is not purchased unnecessarily for a single supported peripheral.
Compare a complete practical connection
Measure the converter cable and the space behind the computer or KVM. A bulky connector can block a neighbouring socket. Include only documented extension arrangements; adding arbitrary chains of adapters makes support harder to establish. Follow the system and peripheral instructions for connection and power state rather than treating legacy sockets as identical to every USB workflow.
US and European buyers should compare exact converter model numbers and local support information. A cheap passive adapter can be a waste when protocol conversion is actually needed, while an active unit can be unnecessary if the peripheral expressly supports the existing adapter. This guide has not tested individual legacy keyboards. The useful purchase is the correct documented direction and feature set for the device already owned.
Compare the trade-offs
| Option | Useful when | Purchase limitation |
|---|---|---|
| PS/2 peripheral to USB computer converter | Older keyboard or mouse must serve a USB host | Check exact supported features |
| USB peripheral to PS/2 system converter | A USB device must serve a legacy host or KVM | Opposite direction requires a different product |
| Documented passive adapter | Peripheral itself supports both interfaces | Not universal protocol conversion |
Your purchase checklist
- Label computer and peripheral sides before ordering.
- Confirm whether active conversion is required.
- Check special keys, KVM and pre-boot support where needed.
Sources and further reading
Reference links concern the stated topic or example. They do not indicate endorsement of this publication. Product versions, local labels, availability and seller terms can change; verify the exact listing before ordering.