Hard to tell without a pic, but I'd guess its a 'DB Connector' or 'Game Port' connector.
DB-15 (DA-15 and DE-15)
Two DB-15 connectors are widely used. The larger, two-row female DA-15 is the game port on a PC, and the smaller, three-row, female high-density DE-15 is the VGA port.
The Game Port was used for joysticks, midi devices and other peripherals.

source
Answer from th3dude on Stack ExchangeCan't find a 15 Pin Sub-D to Mini-USB anywhere
15 pin to usb adapter help
DIY cable/ ALDL to 15 pin serial? - Third Generation F-Body Message Boards
DB15 serial to USB for radio console programming
Hard to tell without a pic, but I'd guess its a 'DB Connector' or 'Game Port' connector.
DB-15 (DA-15 and DE-15)
Two DB-15 connectors are widely used. The larger, two-row female DA-15 is the game port on a PC, and the smaller, three-row, female high-density DE-15 is the VGA port.
The Game Port was used for joysticks, midi devices and other peripherals.

source
A couple of our earlier generation terminal concentrator units ran on an RS-422 loop that used DB-15 connectors and cabling.
Hi,
I am trying to connect a frequency converter to my computer to make it work with a software. Unfortunately the connector I need is from a company that has not replied to any of my emails. Would anyone know if anyone sells this specific adapter?
It is a 15 pin adapter to mini-USB
***Update
Sorry, it didn't seem to attach the picture I wanted to show, here is the link to what the adapter looks like, https://imgur.com/DRpi7nU
This is the website of the manufacture.
https://bmr-gmbh.com/zubehoer.htm
I have the diagram of the pins https://i.imgur.com/LPq3psK.png
I have an old Cyborg joystick with a 15 pin cable. I don't have a port for this on my pc. Is it worth getting a usb adapter? Any recommendations, experience or ideas are greatly appreciated
I am trying to find a way to program an old radio console, a GaiTronics CommandPlus. It interfaces via a DB15 male serial connection. I cannot find a pcie DB15 serial card. Pcie is the only interface other than USB available to me. The easier option though is a DB9/DB25 to USB cable. Then using a DB9/DB25 to DB15 adapter. Looking at old product listings it looks like the radio interfaced with a DB9 to DB15 cable.
Also super annoyed that search results for DB15 lead me to gameport or VGA results. Even filtering out those terms results are not what I am looking for.
Any Amazon products available to do the job? Or information for me to fashion my own DB9/DB25 to DB15 cable? Yes purchasing or finding an old computer is available but comes to "does it have a DB15, if not then I'll need to adapt to DB9/DB25."