My understanding is that it required digital equipment at the exchange end which would make it impossible to do with two standard modems wired back to back. Unless someone has some telco kit laying around, it might be a lost sound.
My understanding is that it required digital equipment at the exchange end which would make it impossible to do with two standard modems wired back to back. Unless someone has some telco kit laying around, it might be a lost sound.
There are other methods but that's the one I would use. To see one of the other methods, try here: https://www.youtube.com/watch?v=yQ_hWS6ked8
V.90/92: https://goughlui.com/2016/05/03/project-the-definitive-colle...
X2: https://goughlui.com/2018/06/10/project-record-a-us-robotics...
K56Flex: https://goughlui.com/2018/06/10/project-record-a-k56flex-dia...
Turns out I've been trying to track down the USRobotics Sportster voice modem sound from your first link. Even better as I can't find my 56k USRobotics, only the 33.6k one, so probably wouldn't have ever found that sound with hardware either.
Thanks; that's been lodged in my head for a couple of decades.