Guide

Yaesu FT-991A on a Mac: CAT control without Wine or a VM

The FT-991A has a built-in USB port, and macOS can talk to it directly. You don't need Windows, Wine or a virtual machine. You only need the right serial port and matching CAT settings on the radio.

1. Connect the radio

Use a plain USB A-to-B cable from the rear USB socket of the FT-991A to the Mac. The radio contains a Silicon Labs CP2105 chip. macOS sees it as a CP2105 Dual USB to UART Bridge Controller and creates two serial ports, plus a USB audio device for digital modes.

Check that the ports exist in Terminal:

ls /dev/cu.usbserial-*

You should see two entries that differ only in the last digit, for example …AF10 and …AF11. If nothing shows up, try another cable or USB port first. On older macOS versions you may need the Silicon Labs VCP driver.

2. Pick the right one of the two ports

This is where most Mac setups fail. The CP2105 provides an Enhanced and a Standard COM port:

On our test radio, CAT only answered on the Enhanced port, the one ending in 0. On the other port there was no response at all. Many programs simply pick the first port they find and then report "no connection".

3. Match the CAT settings

The radio's menu and the software must use the same values:

In our tests the combination Enhanced port + 38400 bps + RTS on was the key. With RTS off, the correct port stayed silent.

4. Test the connection

A real CAT connection answers. The command ID; must return ID0670; (the FT-991A's ID), and FA; returns the VFO-A frequency. If you only get your own command back (an echo), the wrong port or wrong settings are in use.

5. Software on the Mac

Digital-mode programs such as WSJT-X and fldigi run natively on macOS and can control the FT-991A through Hamlib. What is missing on the Mac is a full control surface for the radio itself: VFO, levels, meters, memories and repeater setup in one window.

That is why MacYaesu exists. It is a native macOS app for the FT-991A. It recognizes the Enhanced port and offers it first, only reports "connected" after a real CAT handshake, and remembers the working port. A CAT trace helps when something doesn't work.