[johnzim]

I thought that too. Pulse dialing can’t possibly work anymore. Is OP sure it’s not a retrofit?

[function_seven]

The VoIP gateways we were installing a few years ago still supported pulse dialing on the FXS lines. Those gateways supported all sorts of archaic and arcane POTS features. All the classic feature codes (like *69) had support. I think it could be set up to emulate a DMS-100 or a 5Ess as well.

If you have a copper landline from your local telephone company, I'm willing to bet it still supports pulse dialing? Maybe it's 50/50 now?

[bydo]

There are pulse to tone converters: https://www.dialgizmo.com

[phirschybar]

ha. this just reminded me that some old touchtone phones had a pulse button in case you needed it.

[Stratoscope]

Every POTS phone I've ever seen, touchtone included, has a pulse button. It's the hook switch!