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

[Dave Froble]

On 3/8/2020 5:26 PM, Paul Rubin wrote:
> 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.
>

Well yeah.  More for data transfer than device control, but, I really 
like as a minimum a byte count handshake.  Possibly not possible with 
device control.

But yeah, what are you trying to do?

-- 
David Froble                       Tel: 724-529-0450
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