flow control

William L. Sebok wls at astrovax.UUCP
Thu Dec 13 12:45:36 AEST 1984


> > Personally I think RTS and CTS flow control is less disgusting than XON and
> > XOFF (I think XON, XOFF is disgusting).  I think that flow control should have
> > been done out-of-band whenever possible.
> 
> XON and XOFF *are* out-of-band.  They are control characters, reserved for
> such signalling purposes, not data characters.  Re-read the ASCII standards
> if you don't believe me.

I am quite aware of that.  I realized after I had posted that followup that
it would provoke a response from some pedant.  The article to which I was
replying did not mention ASCII.

What I was objecting to was the statement that use of RTS and CTS for flow
control is disgusting.  I don't have the standards before me but I seem to
remember that was their intended use.  Whether it is or is not the intended
use of these lines. I still prefer methods of flow control be used whenever
possible on 8 bit lines which allow the use of the full 8 bit path.  The
other nice thing about use of such lines is that flow control could have been
done entirely by hardware made transparent to software.  This is what how
I think the standards really should have evolved.
-- 
Bill Sebok			Princeton University, Astrophysics
{allegra,akgua,burl,cbosgd,decvax,ihnp4,noao,princeton,vax135}!astrovax!wls



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