Dr. Prof. John Lions was born on this day in 1937; I had the pleasure of
having him as one of my Computer Science lecturers in the early 70s, and
he drilled into us the Principle of Least Astonishment (or POLA), better
known as "why the fsck did it do that?" (but he was far too genteel to
express it that way). And yes, that's my name in the credits; I helped
with the proof-reading and provided the use of the high-quality printer in
the CSU.
You are not expected to understand this.
--
Dave Horsfall DTM (VK2KFU) "Those who don't understand security will suffer."
Scot Hacker has re-published his BeOS columns for Byte. BeOS was an interesting operating system with a clear Unix inheritance built for a dual-PowerPC system, similar to the Macs of that era.
http://birdhouse.org/beos/byte/
Its inheritance can be found in Haiku (https://www.haiku-os.org)
Arrigo
All,
While it's fresh, I thought I'd share some resources I've found helpful
in learning about the venerable v6 as a relative newb...
Learning Unix V6 in the modern era is an interesting and enormously
educational experience. In the process of using it I have had to learn
how to host it in a simulator (SimH in my case, but there are others),
install it, communicate with it, configure it, build special files for
it, attach devices to it, communicate with the devices attached to it
and to SimH, build a kernel, install the kernel, boot the kernel, work
with a variety of media intended to work with it, extend it, and so on.
In addition, I have had to learn a bit about the PDP-11 (as arguably the
most convenient architecture for learning about V6), about its
architecture, its instruction set, its devices, its memory structure,
and so on.
None of this exploration would have been possible without the excellent
work of Bob Supnik, Mark Pizzolato, and co. on the SimH pdp-11
simulator, the Simh mailing list, Warren Toomey and TUHS for making the
bits available, the TUHS mailing list, PUPS, Bitsavers, and a slew of
readily available documentation and texts including these notables:
Setting Up Unix 6th Edition from the V6 Programmer's Manual
The Unix V6 Programmer's Manual in its entirety
The SimH and SimH PDP-11 Manuals
A large number of blogs with SimH specific V6 installation logs
The V6 Source Code and man pages (don't forget to install man - the 1bsd
version works, and is superior)!
The DEC PDP-11/05-10-35-40 1973 Handbook (the 11/40 handbook is not as
detailed with respect to memory management)
Lions's Commentary on the Sixth Edition source code
Now that I'm over the beginner's hump, so to speak, I'm exploring things
differently and I thought I'd share some resources that I am currently
finding useful and interesting in my explorations...
To bone up on assembly language, Lions's commentary is exceptionally
helpful in explaining assembly as it is implemented in V6. The manual
itself is really thin, and the source is a bit cryptic, for the
newcomer. Lions explains the idioms used in the main source of V6.
However, without a background in assembly language, Lions is pretty
meaningless, so I went looking for something that was PDP specific that
would bridge the gap and help me understand Lions's words. I found a
number of texts that were really good. Most require a working RT11
instance to actually try out the coding examples and do the exercises
(SimH and Bitsavers to the rescue):
Arthur Gill - Machine and Assembly Language Programming of the Pdp-11
Charles A. Kapps and Robert L. Stafford - Assembly Language for the PDP-11
Glenn H. MacEwan - Introduction to Computer Systems: Using the PDP-11
and Pascal
James F. Peters - The Digital Way: Macro-11 Assembler Programming (PDP-11)
Michael G. Schneider - The Principles of Computer Organization: With
Assembly Language Programming for the PDP-11
PDP-11 Processor Handbook (pretty much any edition)
Thomas A. Frank - Introduction to the PDP-11 and its Assembly Language
All of these are useable with a running RT11 instance. But, I think the
Peters and Frank books are the standouts. Peters because all of the
exercises that I have tried (dozens) have worked as printed and Frank
because he is rigorous in his treatment of the subject and builds up
from digital logic all the way through program execution. Frank is an
excellent complement to Lions work because he explains the details that
Lions assumes.
To learn about digital logic, and a special thanks to Warren for his
work on Crazy Small CPU, I have been introduced to logisim. It is a
great playground for exploring digital logic. I had no idea that a
sketchpad for digital logic simulation was available and accessible to
the layperson. Logisim development stopped around 2014 and while there
are a number of successors out there, I am using logisim-evolution:
https://github.com/reds-heig/logisim-evolution
The rabbit trails never seem to end... in order to learn how to use
logisim, I went through the excellent tutorial and then went looking for
a book of experiments in digital logic and found:
digital computer lab workbook from 1969
http://bitsavers.trailing-edge.com/pdf/dec/handbooks/Digital_Computer_Lab_W…
digital equipment corporation computer lab teacher's guide from 1968
http://www.so-much-stuff.com/pdp8/pdf/ComputerLabTeachersGuide.pdf
These two are useable with very little modification as a source of
digital logic exercises that work great with logisim and are related to
the architectural lineage of the PDP-11.
These resources fit together nicely in my pursuit to better understand
digital logic, the pdp-11, assembly language, and unix v6. In sum:
Source code for v6 for what really is supposed to happen in v6 operation
Lions for understanding Unix V6 sources and for unix assembly language
information
PDP-11 Hanbook for quick reference on PDP-11 assembly language
instruction set
Frank for assembly language details and for details on digital logic and
its relationship to the PDP-11 architecture.
Logisim to test logic constructs
The digital lab workbook for practice with digital logic
Later,
Will
--
GPG Fingerprint: 68F4 B3BD 1730 555A 4462 7D45 3EAA 5B6D A982 BAAF
Hi all, Happy New Year. As it's now only eighteen months to the Unix 50th
Anniversary, I thought I'd poll you all to get an update of what is being
done to celebrate the anniversary, and/or what could we organise that has
not yet been organised.
Cheers, Warren
Sir Charles Antony Richard Hoare FRS FREng was born on this day in 1934; a
computer pioneer (one of the greats) he gave us things like the quicksort
algorithm and ALGOLW (a neat language).
--
Dave Horsfall DTM (VK2KFU) "Those who don't understand security will suffer."
Computer pioneer Donald Knuth was born on this day in 1938; amongst other
things he gave us the TeX typesetting language, and he's still working on
"The Art Of Computer Programming" fascicles (I only got as far as the
first two volumes).
I really must have a look at his new MMIX, too; I love learning new
programming languages (I've used about 50 the last time I looked, and I'm
happy to post a list for my coterie of disbelievers).
--
Dave Horsfall DTM (VK2KFU) "Those who don't understand security will suffer."
> I will be happy to forward pertinent suggestions.
Here's one. If Bell Labs holds some kind of symposium on
the lines of the dmr memorial, how about a plenary
session with TV participation from remote venues (think
Berkeley/Silicon Valley and Wollongong/Sydney--a nine-hour
span of time zones).
Any thoughts about this or other possibilities?
Doug
I don't think I'm violating anyone's confidentiality by revealing that
Marcus Weldon, current president of the Labs, at the suggestion of
Martin Carroll, expects the Labs to embark soon on plans to mark
the occasion. I, and no doubt Martin, will keep you posted. Meanwhile
I will be happy to forward pertinent suggestions.
Doug