[Coco] RS232 Schematics, was DriveWire survey

[CoCoList for Color Computer Enthusiasts]

> The main problem is the "number" of latches needed.  That's the reason I
wanted to know the registers for common things.
>
> CPLDs are sold by number of "1-bit latches" (and logic elements, but
that's not important right now).  So, an 8 bit register (as developers know
them) is 8 latches (really, flip flops, but someone else can play the
technical guru here, my explanation will suffice for the topic at present)
>
> In the Xilinx space, the CPLDs are 36, 72, 144, and 288 latches.
>
> BUT...  Onc you get into the 144 or the 265 space, you're getting quite
pricey, and then it's time to move to an FPGA, which offers thousands of
"latches" for not much more money.  For instance, An XC95288XL is $15.00,
but an XC3S100 (which has 73000 latches) is only $10.51.
>

Forgive my ignorance here..  There are 40 pins on the bus connector but
when you ignore power ground and stuff nobody needs its probably ~30 that
matter.

Does that translate to needing 30 latches, or is that not how it works?
Maybe I'm not getting it since you mentioned hundreds and you know there
aren't hundreds of lines on that thing... If you don't mind explaining I'm
interested I'm getting a "high level" understanding of what involved.

Another (to me, the biggest) question: assuming an interface between the
coco bus and a general purpose computer like a raspberry pi existed, could
general purpose software (c or whatever) be used to implement all of the
logic behind such an interface?  Could I write a program that is literally
reading and setting individual lines on the bus connector any which way it
wants (within timing constraints of course)?  Or are we talking about some
intermediate form of communication where the program is talking to
(something) and the coco is talking to (something) but the general purpose
computer isn't directly manipulating the bus state.
Sorry if that's obvious, I haven't quite figured it out :)
Like I said before, I am not even sure if the difference in speeds between
the two systems puts us into the realm of making fully arbitrary
manipulation of the bus possible.  If it does allow that now or in the
future.... My god the possibilities are endless LOL.