[Semibug] Lightning talk - Historic Systems - Simulation Resources

Jeffrey David Marraccini jeff at nucleus.mi.org
Tue Aug 22 19:29:16 EDT 2017

[ Thank you for the great meeting! -- Jeff ]

SemiBUG - Historic Systems - Simulation Resources

Tuesday, August 22, 2017



Even for people that were born after these systems, revisiting them 
shows why our current computing models are so rich and varied.Earlier 
systems will feel crude to us, and even claustrophobic, due to the lack 
of easy and robust networking.It is now quite rare to be totally cut off 
for all forms of communications, and honestly, the early systems helped 
lead the way there, too.The early Internet ran on DEC PDP systems, among 
others!For those of us that actually used these systems day to day, it 
can be a sharp reminder of how far we have come when storage was really 
measured in kilobytes and megabytes, and even an under-configured 
mainframe like the Oakland University Multics system felt like a 
"Cadillac" system!

    Need an idea for a winter project when you are snowed in?

Using a sufficiently powerful computer running BSD, Linux, macOS, or 
Windows, it is possible to run several simulated environments and 
network them together virtually on the host, allowing a basic recreation 
of what the early Internet looked like (ARPANET), with DEC PDP, DEC VAX, 
IBM mainframe, Multics (MIT Multics, OU's Multics never joined The 
Internet directly and had to be reached via terminal emulation), and 
others.For some fun, load a few different 4.3 BSD systems and set up 
shared authentication and host files, and go back to the days of rsh & rcp!

Internet sites like wikidot, wikipedia, bitsavers, archive.org, and 
others have rich materials including scans of original documentation.

    Multics on SIMH:

Often teased about, Multics is indeed a very rich classic computing 
environment that lead to the development of Unix, virtual memory, and 
most recently, is being rediscovered due to its unique (even to this 
day) manner of mapping memory resources to files (segments in Multics 
parlance) that is coming to be relevant again with the rise of 
non-volatile direct access memory.

Check out http://www.multicians.org/ for a huge library of materials 
about this operating system, including simulator resources that work on 
BSD, Linux, macOS, and Windows.

Eric Swenson has a well-organized Multics FAQ at 

Oakland University had a Multics, and Jeff has pieces of it in his 
office.Not long back, an OU Multics CPU panel was brought back to life 
at The Computer History Museum, being driven by the SIMH-hosted Multics 
simulation environment lead by Harry Reed, Charles Anthony, and many 
other people.

Efforts are underway now to get Internet protocols working again, as 
unfortunately, most of the source code for the early Internet software 
for Multics has been lost.However, several people already have Multics 
systems reachable on The Internet using similar techniques that Oakland 
University used back in the day:virtually wire up the FNP to a 
telnet-based terminal server :-)

    Michigan Terminal System:

[ Jeff's Hercules environment will not run on his work computer due to 
restrictions here, my apologies, but there are youtube demos that show 
the environment.]

MTS was an IBM mainframe-based environment that was used by many 
thousands of students, faculty, and staff at The University of Michigan 
for many years.MTS was used to help develop software that lead to the 
rapid expansion of The Internet, and for a while, many sites ran MTS.

It is now possible to simulate MTS on the Hercules IBM mainframe 
simulator, among other IBM mainframe operating systems.It is a direct 
restore of code formerly running at UofM.


    4.3 BSD on VAX via SIMH:

[ Jeff may have to cheat and run Ultrix today as I appear to have 
corrupted the copy of 4.3 BSD on this computer.It comes up very 
similarly, though ]

I (Jeff) spent a lot of time dealing with the 4.x BSD systems as Oakland 
University ran them for Computer Science, Engineering, Chemistry, and 
Physics installations over the years.We had a few small and mid-sized 
systems running 4.3 BSD networked together using early Ethernet 
networks, including a VAX 750, the most lovingly-used system since it 
was basically wide open to all School of Engineering and Computer 
Science students and faculty.

Back in the day, you had to have both AT&T and Berkeley Unix licenses to 
get source and binary tapes to run BSD, but in our modern era, they are 
more easily come by, and running 4.3 BSD can be very instructional!I 
always quickly realize what I am missing, mainly the rich shells we are 
used to today, but all the basics are there even on an initial 
installation, but it is a hard adjustment to switch back to a telnet, 
rsh, and rcp lifestyle from our more encryption-is-mandatory Internet :-)

Easy to set up in the simulator by virtually reading the install tapes, 
4.3 BSD was a very rich environment for its time, and lead to 
development of a lot of commonly-used tools today.On a fast host, it 
still takes quite a bit of time to rebuild 4.3 BSD from its source tapes!



    Apple Lisa on LisaEm:

The Lisa was a short-lived computer that represented Apple's view of 
future computing.Supplanted by Macintosh, it did bring a lot of XEROX 
Palo Alto Research Center technologies into wider view but was always 
hamstrung by very slow storage of the day.The 5MB Profile hard drive 
that was required to run the original Lisa was attached using a "high 
speed" serial port and was only barely faster than floppy discs.The Lisa 
OS also had some architectural issues that resulted in slow performance 
opening and closing files.

Later on, Lisa's hardware was used to run a port of Unix, and still 
later, the oft-dreaded Microsoft/SCO Xenix :-)SCO got its start with 
this port back in 1984.

LisaEm has limited porting targets at present and likely will not work 
on your existing BSD system.Best success is currently had by running 
Windows natively or on emulation using a powerful system.


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