Mark Abene <phiber at phiber.com> wrote:
> I'm posting this here in the hopes that there are other KLH10 emulator
> users on HECnet.
There are, I am one of them.
> I've been using KLH10 with the tap patches for years and years, and idling
> has always worked fine. At some point over the recent couple of years,
> idling stopped working for me on linux (I run ubuntu 16.04.4 LTS with
> latest updates as of yesterday, on a 64-bit intel machine). My CPU is stuck
> at 100% utilization, without even starting an emulated OS (I run TOPS-20).
> In fact, as soon as I type "GO" in KLH10 and before doing anything else,
> the CPU immediately shoots to 100%. Is anyone else seeing this? In older
> versions of ubuntu/linux this didn't happen.
Handful of points:
* the idling is done by modifying the idle loop in the guest operating
system to interact with the KLH10 idler device, not by identifying
the idle loop like SIMH does.
* until the OS is up and running, there is no idling. In other words,
while at the BOOT> prompt there will be a loop consuming 100% CPU
waiting for terminal input. This is normal, and it has always been
* if you have had the same TOPS20 system running, with idling, earlier
everything points at your host os (ubuntu) no longer cooperating with
KLH10. I myself run (mostly) FreeBSD, and I have never had problems
with idling the TOPSxx systems.
* for TOPS10, there are a couple of more things to consider, one of them
is that the idler device by default is at device code 700, which can't
be accessed from the mode the -10 idle code runs in. Using 740 works.
I would look for what has changed in your host os (ubuntu) regarding
system timers and such. Your setup *should* work.
Time for a new release announcement of TCP/IP for RSX-11M-PLUS.
This release contains a lot of fixes and improvements in many areas.
There are a couple of very serious bugs in TCP that is fixed in this
release which is why I really encourage people to upgrade. (They do not
happen often, but if they happen, they have a high chance of crashing
- Stability and reliability improvements in TCP.
- Improved HTTPD
- Improved MAILD
Magica.Update.UU.SE, which is a real PDP-11/70, have now run with the
latest release for over 3 weeks without any issues, so I think it's safe
to say that this product is now very stable. Mim.Update.UU.SE (an
emulated 11/74) have in the same time served over 7Gb of data over FTP,
HTTP and other lower volume channels. (And both of these machines are
more or less fully exposed to the internet, so they see a *lot* of
connections and random attempts to compromise them all the time.)
Detailed information on things that have been done since the last release:
- Improved handling of received TCP push packets.
- Improved TCP ACK handling under lost packet recovery.
- Improved TCP window update handling.
- Bugfix for the condition that a socket was closed while there was
outstanding sends and the remaining window was 0 and the transmission
was not ACKed. This would cause the socket to get stuck in a pending state.
- Improved TCP write handling. The second IOSB word was previously not
set to reflect how much data was written.
- Added new TCP option for sockets to optionally return available data
at read if push was set.
- Bugfix in TCP. An internal data structure was sometimes modified when
it should not be, which could cause a system crash under rare circumstances.
- Improved error handling for CGI pages.
- Improved subprocess handling for CGI module.
- Improved MAILD to handle broken Linux MAIL11 server.
- Improved MAILD error handling.
- Bugfix in MAIL. When composing mails, the temporary file is now
created under SYS$LOGIN.
- Added timeouts for various parts of MAIL11 processing.
- Improved subprocess handling in BASIC+2 library.
- Updated F77 library and documentation.
- Improved performance.
As usual, the distribution is available from:
The documentation is also available through ftp on Mim, or also at
The firewall for Mim have now been removed, so no need for the alternate
ports, but Mim is still listening to the alternate ports as well.
Johnny Billquist || "I'm on a bus
|| on a psychedelic trip
email: bqt at softjar.se || Reading murder books
pdp is alive! || tryin' to stay hip" - B. Idol
I'm posting this here in the hopes that there are other KLH10 emulator
users on HECnet.
I've been using KLH10 with the tap patches for years and years, and idling
has always worked fine. At some point over the recent couple of years,
idling stopped working for me on linux (I run ubuntu 16.04.4 LTS with
latest updates as of yesterday, on a 64-bit intel machine). My CPU is stuck
at 100% utilization, without even starting an emulated OS (I run TOPS-20).
In fact, as soon as I type "GO" in KLH10 and before doing anything else,
the CPU immediately shoots to 100%. Is anyone else seeing this? In older
versions of ubuntu/linux this didn't happen.