Here’s a Windows application I recently whipped up to control my vintage Sony U-matic deck. It handles basic transport functions only — no editing — but all the controls work exactly as you’d expect and I enhanced the time counter with an unlimited locator memory. It will operate nearly any Sony professional VCR and many other devices that use Sony’s P2 protocol, also known as “9-pin” and “RS-422.”
To use this program, you’ll need a computer with an RS-422 serial port connected to your slave device. These days, the simplest option is a USB converter dongle. Pinouts vary a lot, so take some time to make sure the right signal is going to the right place. You can check out the standard Sony connection details here.