We still need specialized hardware for this?

Posted Aug 22, 2022 16:15 UTC (Mon) by farnz (subscriber, #17727)
In reply to: We still need specialized hardware for this? by immibis
Parent article: The growing image-processor unpleasantness

Not legally. Underlying the problem with WinModems was the issue that it was outright illegal in many jurisdictions to write DSP code for a part directly attached to the phone line (you'd have to use an acoustic coupler to avoid the regulations).

Even ignoring the legal stuff (which people like Richard Close and Pavel Machek did, and wrote working DSP code), you have the problem that compute resources of the era weren't great, and thus the DSP mostly ended up running in kernel space to meet the required real time guarantees. It was done, and WinModems were made to work, but they were never great - and by the time compute resource was good enough to run the entire DSP in userspace, people had moved away from dial-up.