[Coco] Becker port

[Jeff Teunissen]

On the IRC channel, some of us were discussing the DriveWire "Becker port"
implemented in emulators and the CoCo FPGA. Specifically, someone thought
it was something that you would build a cable for with a regular CoCo,
perhaps thinking it was related to the bit-banger. We got the confused
person straightened out without too much trouble, and explained what the
Becker port really was, a dedicated serial DriveWire link.

We started wondering how useful it might be to have a real-life version of
the Becker port -- a serial port connection that presents as a read status
port at $ff41 and a read/write port at $ff42, with enough buffer space to
fully contain a 'sector read' response, and possibly be able to run at very
high bit rates without requiring all the CPU a CoCo can apply to it.

Might such a thing (a high-speed DriveWire accelerator program pak) be
useful/desirable?