In my workplace we use an old software that accepts keyboard input, but only from a keyboard that's connected to a COM port. We have an old converter that has a PS2 keyboard input and converts it to RS232 which then connects to the computer.

We'd like to switch to more modern, ergonomic USB keyboards and unfortunately the company that makes these adapters no longer exists.

We tried the following:

  1. Using a USB to PS2 converter: We tried to use a USB keyboard with a PS2 converter. That didn't work, probably because the converter isn't active AND the keyboard does not support both USB and PS2.
  2. Using a USB to RS232 converter: We tried to straight up connect the keyboard to the RS232 port using a cable converter. The cable was recognized, but the keyboard didn't get any power. We even tried to strip the keyboard wires and connect another USB port to it for power from the computer. That didn't work.

Recently, we found the this product. This product claims to convert any old RS232 peripherals to USB port and they also include drivers to trick the computer into thinking it's RS232.

We bought the adapter, but it works the other way around. It adapts legacy RS232 devices to modern USB ports. However, there may be another way.

What if we connected a USB keyboard to a USB to RS232 converter, connected that to the module and then connected it to the computer, would that work?

Because these converters aren't cheap and we already blew a lot of money on this, I wanted to ask here if this solution will work or do you guys know any other solution that might work. We really tried everything and haven't found any solution, but I really believe there MUST be an easier way to perhaps trick the computer into thinking we connected a keyboard to it's COM port even though it's USB keyboard, even something like a software emulator.

Thanks, if I missed any information please let me know.

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    can you determine if the rs232c input required conforms to TTY communications protocol?
    – fred_dot_u
    Commented May 6, 2019 at 16:09
  • (1) Your attempts ignore the fact that USB connections are hierarchical/directional. A USB device must connect to a USB host (e.g. a PC with a Type A port). You cannot connect a USB device to another USB device. (2) You need to look for a converter that specifically supports a PC keyboard input, i.e. the keyboard scancode must be converted to ASCII code for RS-232 transmission. A USB-to-RS232 converter doesn't understand keyboard scancodes, not at the electrical signal level nor the binary code level.
    – sawdust
    Commented May 7, 2019 at 2:37

1 Answer 1


Versalent makes just what you are looking for WLKB232-xxx . Converts a USB wired or even wireless keyboard into plain old RS232 characters out. www.versalent.biz

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    That looks like a perfect solution. But do you have any recent experience with them? The web site design is rather old (not a crime), copyright listed as 2012. So I wouldn't try buying without calling them first to make sure they still exist and can still ship the product. But the price is right. Commented Jun 11, 2019 at 21:56
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    Yes I do have some experience with them since I own/run the company :) And yes the site is old, (as am I) -- which means the products have a lot of design experience behind them and are reliable, and perform as advertised. Current stocked quantities are listed in the left navigation pane for each product. Commented Jun 12, 2019 at 3:10
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    While personally I would likely jump at such a product if I needed it, you should include full disclosure in the message. Advertising in answers is frowned upon in general in StackExchange, though personally I don't see it as a bad thing if the product is the solution to the question - which is indeed the case here. But failure to disclose any personal interest in a product is a much bigger problem. Commented Jun 12, 2019 at 3:23
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    I consider 'advertising' the unsolicited distribution of product/sales information. Directing someone to a site (even if my own) when they asked about the availability of a particular product they were unable to find -- seems like a helpful service more than self-promotion. Should I withhold such info when it solves their problem? Commented Jun 12, 2019 at 12:52
  • Don't withhold it. Just disclose it - My company, Versalent... Clearly since nobody else had an answer for a month, the answer is worth posting. Commented Jun 12, 2019 at 14:27

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