Re: ports

> This brings up a question that has always bugged me.
>
> Why do they let you so easily read and write serial data, but make it very
> difficult to do the same with parallel data?

How so? If you're talking about from a "write your own driver" level,
programming the 16550 (serial chip) is a hell of a lot harder than
programming the parallel port.

If you're talking about from a "talk to the driver via APIs/IOCTLs" level,
well, people play with serial ports a LOT more than they play with
parallel ports. Since the parallel port architecture on the pc SUCKED
SO MUCH the only thing most people did with it was hook up printers and
pray that they worked..

For people that tried to do things like "bi-directional communications",
well, let's just say that it is GROSS. Incoming communications are usually
done a couple of bits at a time (using the control signals, since the
databits are one way in the orig design).. Now that people have put out
ECP and such life is easier.

Sorry for the rant.. I'm still having flashbacks of working on those
drivers.. Never, Ever look too closely at how the Xircom parallel port
ethernet card worked.. *bleagh* (but it did work, gotta give 'em credit
for getting that much!)

Kurt
Received on Thu Jul 22 17:01:04 1999