[ih] uucp, was Question re rate of growth of the Arpanet

[Johan Helsingius]

On 23/04/2025 14:30, Jaap Akkerhuis via Internet-history wrote:
> Well, it was all we had at that time, Also, one had to toggle
> switches by hand which was a bit clumsy so we had this little box
> built to do it remotely. Later on we could get our hand on 1200 bps
> and even 2400 bps (but don't tell the regulators). The dialler boxes
> became a great succes and somehow spread over Europe.

We fortunately managed to get a semi-prototype Nokia dialler.

> When the X.25 DN-1 came available foe international traffic, we
> startad to use that as well.  It also gave birth to the f-protocol.

We were running a Zilog Z8000 box, with their port of System III UNIX.
The Zilog guys had noticed the discrepancy between the termip manual
page description and what the code actually did - but unfortunately
they fixed the code to do what the man page said, and not the other
way around. The result was that if both c_cc[TIME] (read timeout time)
and c_cc[MIN] (number of characters to buffer) were non-zero, the
Zilog code counted the timeout from the beginning of the read()
system call, not from the first character. Thus if the sending host
was slow, the read() might time out before any characters are read,
resulting in 0 characters being returned - the signal for line being
dropped. Not fun when most of a large packet has been received (and you
are paying per byte/X.25 packet transferred.

Cost us a fair bit of X.25 charges until I figured it out. Couldn't
fix the tty driver (no kernel sources), but could do a workaround
in the UUCP code (from Piet).

	Julf