[Info-vax] Using terminal lines - a long shot question

[Paul Rubin]

Lee Gleason <lee.gleason at comcast.net> writes:
> it described when to use what sort of read qio's, from single
> character reads with timeouts to bulk reads by length, and several
> types in between those, and when to switch to which variety. It went
> on at length how to do this sort of thing efficiently and reliably.

I don't know what entry you're referring to, but assuming this is in a
PDP-11 or VAX context, I'd expect the details of how best to do this
would depend very much on the serial port hardware.  There were a lot of
different serial interfaces for those machines, that had or lacked
various affordances like buffering, DMA, on-board controller that could
handle some protocol complexity, etc.

If you are asking how to design a wire protocol in general, that's not
terribly OS specific.  Obvious tips like include a version field and
suitable checksums come to mind, and don't rely on realtime flow
control.  Other than that, writing precise specs gets you a long way.