> From: Mouse
> It's true that C is easy to use unsafely. ... I suspect it is not
> possible to eliminate the ability to do stupid things in C without also
> eliminating the ability to do some clever things in C.
Oh so true. Computer science progress seems to be all about improving on
getting the most bang for the buck (i.e. it's really engineering, which is
all about bang/buck ratios - as the saying goes, 'an engineer is someone who
can do for $.10 what any fool can do for $1').
So assembly language is maximally flexible, but very easy to screw up.
Something like C gives you 93% of the flexibility, but with only 40% of the
chances to screw up. (Numbers only approximate, after 2 seconds of
consideration.) So further language development has had to improve on that
ratio; ideally, one should decrease the latter with impacting the former, if
possible - a non-trivial problem.
And of course the optimal flexibility/screwage ratio will differ from
programmer to programmer, and even from project to project. (I once wrote a
condition handler package for C, and elected to do it in assembler - even
though others have done in it C, using longjump(). But there are very few
things where assembler seems a better choice, to me.)
> Note that PDP-11 autoincrement and autodecrement exist only when
> ... the pointers are in registers.
Of course, clever programmers will make sure their code is arranged (not
warped into an non-understandable maze, mind, just... arranged properly) to
do that! :-)
But to really do that effectively, you have to be able to control which
variables are in registers, etc, etc. Modern optimizing compilers like to do
this all for you - and do an incredibly good job, most of the time, to the
point where for most programmers, the compiler does a _better_ job than they
could. So, for 97% of programmers, probably the right thing.
For those who are writing real-time code, know exactly what instructions any
piece of code will compile into, and how many memory references are involved,
not so much. (Back to different strokes for different programmers.)
(Yes, yes, I know those optimizations often aren't portable - I wrote a fair
amount of code that ran on several architectures at the same point in time.
But what was optimal on one was usually pretty good on the others, too.)
Noel
Sorry for the OT post but I'm pretty sure someone here
will know how this stuff works...
An office near me was recently demolished/remodeled.
It had retrofitted LED lighting in fluorescent fixtures.
The remodelers were smart enough to save the "bulbs" but
not smart enough to save the "ballasts" (DC power
supplies). Once they figured out that they couldn't
easily use them, they gave a bunch to me. I'd like to
use them but I'm having a little trouble figuring out
how. The "bulbs" are labeled:
15F18120-45 15 watt 36vdc constant current
I'd like to put four in a fixture and I'm trying to
understand what kind of driver I need and how to wire
it. I was thinking of using a Mean Well LPF-60D-36
like this:
http://www.ebay.com/itm/Mean-Well-LPF-60D-36-AC-DC-POWER-SUPPLY-Dimmable-LED
-DRIVER-36V-60W-CLASS2-/161857068172?hash=item25af6edc8c:g:9hQAAOSwA4dWHVn5
and wiring the "bulbs" in parallel to it. But after
realizing that I'm not completely sure what a "constant
current" power supply does and doing a little "googling"
I don't know if that's the right approach.
Any help greatly appreciated,
Bill S.
I can more or less agree with your sentiments, but given the choice of needing to maintain compatibility between many applications and being able to support multiple architectures such as SPARC and Power Gentoo is really the only choice.
The only real close candidate would be FreeBSD which treats anything that isn't x86 as a second class citizen. I have my own issues with Linux as well, and as I said earlier I would much rather use illumos, but when it comes to business applications that always have to run and always maintain compatibility is new versions come out gentoo is as close to a BSD/Unix that I can get to and maintain compatibility with everything I need.
Use flags can be cumbersome if you have tons of applications such as a desktop system. But that's generally not the case for servers which is really all I care about in this case. For me it's generally just maintaining a set of used flags for each application that I need which is generally pretty minimal per server / container.
Profiles help make Use flags not as cumbersome, but it doesn't quite fix the issue.
Sent from my T-Mobile 4G LTE Device
-------- Original message --------
From: Swift Griggs <swiftgriggs at gmail.com>
Date: 4/29/2016 12:10 PM (GMT-05:00)
To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org>
Subject: Gentoo (was Re: strangest systems I've sent email from)
On Fri, 29 Apr 2016, alexmcwhirter at triadic.us wrote:
> Gentoo is powerful because you get to chose your init system, kernel
> options, and every other piece of software that runs on the box.
Other than the swapping init systems, many OSS OS distributions have the
ability to choose what you want to run. Not all are as granular as Gentoo
(but some, say embedded distros, have even more control). There are dozens
of Linux distros as you know, and this degree of control & granularity is
one of the main variable. Ubuntu users want "just-worky-ness", Gentoo
users often want tweakability in the extreme. It all depends on your needs
and value system.
> For example, dovecot on ubuntu pulls in ldap, sasl, etc... On gentoo you
> choose what gets pulled in via USE flags.
I guess there is no accounting for taste. I would not call USE flags a
feature, my opinion is that they are painful in implementation (dragging
around a list of way-too-many little keywords is not fun, IMHO), nasty to
work with and have to look at (some giant wrap-around variables in the
conf file), and make me feel dirty and disorganized. Plus, in my
experience, if you accidentally put in two mutually exclusive or
not-very-well-tested USE flags you are in for a hard time that might be
difficult to track down (ie.. if the effects don't immediately surface).
> CrossDev is also a great to that has helped me port gentoo to SPARC64
> with little to no issues.
Cross compiling is neat, for sure. However, Gentoo doesn't have any unique
claim on that (not that you implied that). Many other OSs have used the
same methodology since long before Linux, much less Gentoo.
-Swift
I just complete a project to reproduce some old game boxes. I got
tired of the ripped and broken boxes I have for my Color Computer
Program Paks. I made a video about it:
https://youtu.be/5L9adQlM7ro
--
--
tim lindner
"Proper User Policy apparently means Simon Says."
Several years ago, Lyle Bickley began negotiations with S&H Computer Systems
to release TSX-Plus (a 3rd party Multiuser Operating System for PDP-11's) as
free software for personal use. As is often the case, this process can take
a lot longer than one would expect.
Once Lyle obtained an initial agreement from the owner of TSX-Plus, he then
had to await the approval from S&H's Board of Directors. Initially, S&H
chose to only release the source code listings for TSX-Plus (which are now
on Bitsavers.org). Unfortunately, the machine readable source code itself
had been accidentally lost when S&H changed PDP-11 computer systems
in-house.
Eventually, Lyle was able to obtain the original SMD hard drive from S&H
containing the latest versions of TSX-Plus, and the layered products
COBOL-Plus and RTSORT (and other software that remains private to S&H
Computer Systems). He transferred the TSX-Plus, COBOL-Plus, and RTSORT files
to an RL02 disk - and using S&H's proprietary licensing software created a
"personal use, serialized version" of TSX-Plus. This version has ALL the
capabilities and features of the commercially licensed version of TSX-Plus.
Subsequently, Lyle was authorized to release this "Personal Use" TSX-Plus
distribution only to individuals that he could vouch for as being
non-commercial users.
After another year or so, he was able to obtain the current agreement and
license to make this "Personal Use" TSX-Plus distribution generally
available for non-commercial use.
Please note that TSX-Plus is NOT public domain software; S&H retains all
rights including ownership. They have provided a free personal use license
available through Bickley Consulting West. There is still a paid commercial
use license available directly from S&H.
We all owe a big "Thanks!" to Harry Sanders at S&H Computer Systems and his
Board of Directors for making this release a reality for all vintage
computer folks! Also, the hobby owes huge thanks to Lyle Bickley for
tirelessly pursuing this for us all! I've always been a huge fan of TSX-Plus
and I'm thrilled there's now a personal (hobbyist) license thanks to Lyle.
The distribution is at http://tsxplus.classiccmp.org
Best,
J
I have been cleaning a PDP-8/e front panel and some of the switches
are not as free as others. The switches are simple slider basic
switches. I have taken similar switches apart and noticed that there
is a brown/red grease on the contacts.
Any suggestions on the proper grease for a low voltage contact.
Chuck
Excellent news. Thank you for making this happen.
--
Will
On Apr 28, 2016 1:22 PM, "Jay West" <jwest at classiccmp.org> wrote:
>
> Several years ago, Lyle Bickley began negotiations with S&H Computer
Systems
> to release TSX-Plus (a 3rd party Multiuser Operating System for PDP-11's)
as
> free software for personal use. As is often the case, this process can
take
> a lot longer than one would expect.
>
> Once Lyle obtained an initial agreement from the owner of TSX-Plus, he
then
> had to await the approval from S&H's Board of Directors. Initially, S&H
> chose to only release the source code listings for TSX-Plus (which are now
> on Bitsavers.org). Unfortunately, the machine readable source code itself
> had been accidentally lost when S&H changed PDP-11 computer systems
> in-house.
>
> Eventually, Lyle was able to obtain the original SMD hard drive from S&H
> containing the latest versions of TSX-Plus, and the layered products
> COBOL-Plus and RTSORT (and other software that remains private to S&H
> Computer Systems). He transferred the TSX-Plus, COBOL-Plus, and RTSORT
files
> to an RL02 disk - and using S&H's proprietary licensing software created a
> "personal use, serialized version" of TSX-Plus. This version has ALL the
> capabilities and features of the commercially licensed version of
TSX-Plus.
>
> Subsequently, Lyle was authorized to release this "Personal Use" TSX-Plus
> distribution only to individuals that he could vouch for as being
> non-commercial users.
>
> After another year or so, he was able to obtain the current agreement and
> license to make this "Personal Use" TSX-Plus distribution generally
> available for non-commercial use.
>
> Please note that TSX-Plus is NOT public domain software; S&H retains all
> rights including ownership. They have provided a free personal use license
> available through Bickley Consulting West. There is still a paid
commercial
> use license available directly from S&H.
>
> We all owe a big "Thanks!" to Harry Sanders at S&H Computer Systems and
his
> Board of Directors for making this release a reality for all vintage
> computer folks! Also, the hobby owes huge thanks to Lyle Bickley for
> tirelessly pursuing this for us all! I've always been a huge fan of
TSX-Plus
> and I'm thrilled there's now a personal (hobbyist) license thanks to Lyle.
>
> The distribution is at http://tsxplus.classiccmp.org
>
> Best,
>
> J
>
>
Hi All,
Hopefully you all read in the "Notes" (and Jay's and my comments) that
TSX-Plus requires RT-11 as a prerequisite.
RT-11 is readily available all over the Internet.
It is also available at on the classiccmp server at
http://www.classiccmp.org/PDP-11/
Cheers,
Lyle
--
73 AF6WS
Bickley Consulting West Inc.
http://bickleywest.com
"Black holes are where God is dividing by zero"
> From: Liam Proven
> There's the not-remotely-safe kinda-sorta C in a web browser,
> Javascript.
Love the rant, which I mostly agree with (_especially_ that one). A couple of
comments:
> So they still have C like holes and there are frequent patches and
> updates to try to make them able to retain some water for a short time,
> while the "cyber criminals" make hundreds of millions.
It's not clear to me that a 'better language' is going to get rid of that,
because there will always be bugs (and the bigger the application, and the
more it gets changed, the more there will be). The vibe I get from my
knowledge of security is that it takes a secure OS, running on hardware that
enforces security, to really fix the problem. (Google "Roger Schell".)
> The Lisp Machines and Smalltalk boxes lost the workstation war. Unix
> won, and as history is written by the victors
Custom hardware for running LISP lost (not sure about Smalltalk, don't know
much about it), I am quite sure, mostly because 'mainstream' CPUs got so much
faster/cheaper, because of the volume. I saw this happening in the AI Lab at
MIT: when you could run LISP on a workstation with a vanilla CPU much faster
than a specialized LISP processor, that's all she wrote. (That effect killed
all sorts of things, not just LISP machines, of course.)
Noel
