[cctalk] RS232 - parallel modems!?

I was about to ask if anyone ever built a "Parallel Modem" - but I searched around first, and lo and behold, Microcom did ! (v.fast / v.34 era, c. 1996) The drivers refer to Win3.1/Win95 era (I'm not seeing where they had DOS support). But I'm still not sure if I'm understanding the product (which I found described here Microcom Parallel Port Modem <https://strom.com/pubwork/cw294.html> From a programming perspective, you just set your parallel bits and mash the STROBE pin, right? Then figure some reasonable delay between iterations of doing that. You don't need starts/stop or parity bits. So I get how that is more efficient (but question is, why wasn't it built sooner? I think it's a long answer when you look at the historical build up of modems, and that serial-port based modems were "fast enough" at the time) So.. If you had a slow system that couldn't really take advantage of a ~7MHz 16550 serial card (or I guess like a laptop that was stuck with an older UART) That might be the use-case where this parallel v.fast might help (by being able to "feed the modem" fast enough to actually take advantage of the faster modem speed?) Or is there some other scenario NOTE, in the articled linked above, it does mention that it is only "value added" if you have this parallel-modem on both sides of the connection. (this is because you'll be flow controlled to whatever is the slower device in the connection?) Related but different question: Is there any "natural rate" (Hz) of a modem? Meaning is 1200/2400 baud-equivalent modem an accelerated-by-enhanced-encoding version of 300 bps? and 9600 likewise an accelerated-by-encoding version of 2400? is 300bps itself some kind of special accelerated-by-encoding? I see 1200 baud was also still sub 3KHz (did any modem protocol go above 3KHz?). Or maybe I need to ask it this way: did 300 baud modems use a more 1:1 translation of the data-word bits into Hz signal over the modem (giving a more "natural" translation rate?) But then beyond that speed, does a modem need to "cache" a few bytes and determine some encoding scheme to then give modems an apparent speed boost? (is that "kind-of" like USB's 8B/10B? (not in implementation, but in the general concept that a different encoding can result in improved data throughput, without actual faster movement of that data?) I guess it gets into the "secret sauce" approaches of how vendors figured out these encoding approaches (v.32bis, etc), and give their product competitive advantages (but only if you could convince enough ISPs to adopt your protocol, by buying your modem device). My daughter made me finally watch Blackberry recently, it's an interesting telling of that story (of a small business selling their tech to USR, and also that they tackled a version of encryption) -Steve