[ih] X.25

[Johan Helsingius]

On 01/10/2025 23:15, Lyndon Nerenberg (VE7TFX/VE6BBM) via 
Internet-history wrote:
> I think X.25 got more of a workout as a transport layer for UUCP
> (f protocol).  UUCP over X.25 hauled a lot of email and Usenet
> traffic in the 1980s.

I was running the Helsinki-Amsterdam (penet-mcvax) EUnet
backbone connection on UUCP over X.25 back in the 80s, carrying
a lot of email and USENET traffic.

I had a real horror story running a Zilog Z8000 system, with a Zilog
implementation of System III. Unfortunately they, just like everybody
else, noticed the discrepancy between the UNIX TTY termio interface
implementation and documentation, but unlike everybody else, they
fixed the code, not the documentation.

The Zilog TTY driver, in raw mode, would not wait for a certain
number of bytes and a certain time before returning, but would
return after a certain number of bytes *or* a timeout.

If mcvax was slow, the tty driver would occasionally time out -- and
return with 0 bytes, (that UUCP of course took as "line dropped"),
and that transfer of a news or email batch would have to re-start, all
while paying for traffic per data packet (oh, PTT's). Bills got pretty
expensive pretty fast.

	Julf