Have IrDA dongles really gone the way of the dodo?

News to me...

I would have guessed that if the devices met the IrDA standards then comparibility wouldn't be an issue. I know some of the low power devices used a shortened pulse width but kept the same timing cycle.

Unless you are speaking about the baud rate of the SIR, I don't know about compatibility issues.

Which is why for all my vintage handhelds I own/use vintage infrared devices.

A bit late, but as I have now found a FIR adapter:
https://s.click.aliexpress.com/e/_Dk1fFsx

<ponder> It says XP only, but in theory, depending what it IDs as (USB device class wise) one could write an updated driver for it. The main issue is likely that the legacy driver likely just treated it like a COM port or the like and then leaned on Windows for the FIR stuff. So some of the stack would potentially need to be shoved into the other bits... I should grab one for yucks, I'm just worried most of it is in Chinese.

I purchased one on eBay, and that was a pain to get working - I got based on the MCS7780 chipset (Syba USB 2.0 IrDA 1.3)

it was a little pricey but not too bad I paid $24.50 for it - the driver worked on Windows 11 (I think I used the 7 x64 driver) on either the CD or website

Those diver computers for diving use IrDA to communicate, that's how I found more info

It says further down

I use a Polar IR USB stick I bought a couple of years ago, not tried it on W10 but works great for syncing on XP

Struggling to find anywhere selling it now though
Not sure if I trust this site to purchase from but.... https://www.fitsense.co.uk/polar-ir-usb-stick.htm

I do miss the ease of IR for sending small flies, no annoying pairing and failing like with Bluetooth