[HECnet] Re: Hecnet addition

[Johnny Billquist]

Paul Koning wrote:
"Johnny" == Johnny Billquist <bqt at softjar.se> writes:
Johnny> I wonder why you can't set it from NCP though? Weird if they
Johnny> have the functionality, but no "normal" way of enabling it.
>>   Probably history.   I created the async DDCMP driver when I was
>> doing the (unreleased) PRO port for RSTS (9.6 originally).   I
>> handed it to RSTS development, and they integrated it into the
>> release.   But I personally never did the NCP work.   Probably
>> because it wasn't familiar code and it would have been a lot of
>> work.   Instead, I just wrote a little 10 line utility to issue the
>> line on/off syscalls to the kernel.
Johnny> Way fun, and impressive. Thanks for that piece of information
Johnny> and history.   I guess they didn't see much need of DDCMP
Johnny> support in RSTS/E at that point. How did you select which
Johnny> serial port it would use, by the way? Or was this only done
Johnny> for the PRO?   Hmm, I guess it could have been passed in in
Johnny> the syscall...
There is an "assign" syscall (which normally in RSTS means "reserve
this device for me even when it's not open") which binds a ddcmp
driver pseudo-device unit to a tty device unit number, via a syscall
parameter.   So you could have, say, up to 8 ddcmp ports, and those
could be bound at runtime to any of your terminal ports.

Way nice. In RSX, you need to reserve the whole controller at netgen, and no ports can be used by anything else than DECnet if you set it up. DECnet/RSX has its own device driver for the serial port cards.

	Johnny