Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.

Messages - netfreak

Pages: 1 ... 18 19 [20]
Computing, Internet & Technology / Install IOS 7 on Cisco PIX 506E
« on: December 09, 2012, 12:59:36 am »
So… I bought a Cisco PIX 506E on eBay for $40 with the intention of turning it into a transparent firewall. After I bought it, I discovered PIX 6.3 (the highest version available for the 506E according to Cisco) only offers routing mode firewall. This just wouldn’t do. I google’d for a good hour and then got down to it. Here is how I installed PIX OS 7.12 onto my 506E. Required things: PIX 506E with a good 96mb RAM or more, another computer running TFTP, PIX OS image (7.12 is probably the latest that would work within the 8mb flash limit).

1) Boot the PIX 506E into monitor mode (hit esc during boot when it says so)
2) Configure the IP/gateway details of the PIX interface, and the file/IP of the TFTP server (pretty straight forward, type help for command list)
3) Run the TFTP and watch as your PIX downloads and boots into the new PIX OS
4) Configure the connected interface as you will need to TFTP again. Keep in mind you’re now using much different command syntax compared to the PIX 6.x stuff.
5) Do “format flash:” to erase the flash memory
6) Do “copy tftp flash” and enter TFTP server details and new PIX OS image name
7) Wait a while…
8) Should be written to flash memory. Go ahead and reload the PIX and boot off flash

Apparently in later versions of 7.x they added something to prevent it from being installed on a PIX 506E. People have got around it by changing instances of 506E to 515E throughout the PIX OS image. Also keep in mind you only have 8mb of flash to hold the image, and 7.12 runs in around 6.5mb.

Computing, Internet & Technology / Virtuozzo tips and tricks
« on: December 09, 2012, 12:59:03 am »
Virtuozzo Tips and Tricks
July 13th, 2007

Here are some easy tips and tricks for accomplishing more with SWsoft’s Virtuozzo virtualization software. Much of the included information should also apply to the open source OpenVZ software.

Enabling TUN Access for a VE
# vzctl set <VEID> –devices c:10:200:rw –save
# vzctl exec <VEID> mkdir -p /dev/net
# vzctl exec <VEID> mknod /dev/net/tun c 10 200
# vzctl exec <VEID> chmod 600 /dev/net/tun

Shell Script: Execute command on all VEs
for i in $(vzlist -H |awk {’print $1'}); do
if [ “$i” != “1? ]; then
vzctl exec2 $i “command; next command”
done ;

Setting higher iptables rules limit (for CSF, etc)
# vzctl set <VEID> –numiptent 400 –save

VZ external mount points
# mount –bind /dev/<device> /vz/root/<VEID>/<mountpath>

Setting VE Quotas
# vzctl set <VEID> –quotaguid 2000
# vzquota on <VEID> -p /vz/private -r 0 -s 1 -u 2000 -b <soft diskspace> -B <hard diskspace> -i <soft inode> -I <hard inode>

Separating RAM and SWAP in VE
This particular issue is seen within an environment. Instead of showing separate dedicated RAM and SWAP, both numbers are added together as RAM and SWAP shows as zero. SWsoft techs report that this will not cause a performance problem, but can be fixed using this command on the hardware node:
# sysctl -w slm.task_group_priv=1000

If you're using Virtuozzo or OpenVZ to run multiple containers with the intention of connecting between them internally, you'll want to add a static route for the internal network on each container:

route add -net netmask dev venet0

Without this, communication internally does sometimes work but seems to often timeout or fail completely posting data to an internal only container.

Another option for communicating between VEs without using public IPs is via bridge interface. The following can be used to create a bridge:

modprobe -o dummy0 dummy
ifconfig dummy0 up
brctl addbr vmbr10
brctl addif vmbr10 dummy0
ifconfig vmbr10 up

Computing, Internet & Technology / Useful Linux commands
« on: December 09, 2012, 12:57:57 am »
Find large files over 100mb on the filesystem:
find / -type f -size +100000k -exec ls -lh {} \; | awk '{ print $9 ": " $5 }'

Remove empty directories (recursive)
find -depth -type d -empty -exec rmdir {} \;

Replace character (char1) in Linux filenames with another (char2)
for filename in `ls` ; do mv $filename `echo $filename | sed s/char1/char2/` ; done

Replace spaces in filenames with underscores
for file in *; do mv "$file" `echo $file | sed -e 's/ */_/g' -e 's/_-_/-/g'`; done

Computing, Internet & Technology / Philosophy behind Freenet
« on: December 09, 2012, 12:51:40 am »
The Philosophy behind Freenet 

                By Ian Clarke

                1. A Disclaimer

                There are many reasons why people get involved in the Freenet Project. Some share the
                views outlined in this document; some share variations of these views, which are also
                served by what we are trying to achieve; and some just enjoy the technical challenge.
                These are the ideas which motivated me to architect the system in the first place, but not
                necessarily the views that everyone involved in the Freenet project holds.

                2. Suggested prior reading

                For this document to make sense, you should probably know what Freenet is. You can get a
                good overview on the What is Freenet? 

                3. The importance of the Free flow of information

                Freedom of speech, in most western cultures, is generally considered to be one of the most
                important rights any individual might have. Why is the freedom to share ideas and opinions
                so important? There are several ways to answer this question.

                3.1 Communication is what makes us human

                One of the most obvious differences between mankind and the rest of the animal kingdom is
                our ability to communicate sophisticated and abstract concepts. While we constantly
                discover that animal's communication ability is more sophisticated than previously
                assumed, it is unlikely that any other animal approaches our own level of ability in this area.

                3.2 Knowledge is good

                Most people, given the option of knowing something and not knowing something, will
                choose to have more information rather than less. Wars have been won and lost over who
                was better-informed. This is because being better-informed allows us to make better
                decisions, and generally improve our ability to survive and be successful.

                3.3 Democracy assumes a well informed population

                Many people today live under democratic governments, and those who don't, probably want
                to. Democracy is an answer to the question of how to create leaders, while preventing them
                from abusing that power. It achieves this by giving the population the power to regulate their
                government through voting, yet the ability to vote does not necessarily mean that you live in
                a democratic country. For a population to regulate their government effectively it must know
                what their government is doing, they must be well informed. It is a feedback loop, but this
                loop can be broken if the government has the power to control the information the population
                has access to.

                4. Censorship and freedom

                Everyone values their freedom, in fact, many consider it so important that they will die for it.
                People like to think that they are free to form and hold whatever opinions they like,
                particularly in western countries. Consider now that someone had the ability to control the
                information you have access to. This would give them the ability to manipulate your
                opinions by hiding some facts from you, by presenting you with lies and censoring anything
                that contradicted those lies. This is not some Orwellian fiction, it is standard practice for most
                western governments to lie to their populations, so much so, that people now take it for
                granted, despite the fact that this undermines the very democratic principals which justify the
                government's existence in the first place.

                5. The solution

                The only way to ensure that a democracy will remain effective is to ensure that the
                government cannot control its population's ability to share information, to communicate. So
                long as everything we see and hear is filtered, we are not truly free. Freenet's aim is to allow
                two or more people who wish to share information, to do so.

                6. Isn't censorship sometimes necessary?

                 Of course no issue is black and white, and there are many who feel that censorship is a
                 good thing in some circumstances. For example, in some European countries propagating
                 information deemed to be racist is illegal. Governments seek to prevent people from
                 advocating ideas which are deemed damaging to society. There are two answers to this
                 however. The first is that you can't allow those in power to impose "good" censorship,
                 without also enabling them to impose "bad" censorship. To impose any form of censorship
                 a government must have the ability to monitor and thus restrict communication. There are
                 already criticisms that the anti-racism censorship in many European countries is hampering
                 legitimate historical analysis of events such as the second world war.
                 The second argument is that this "good" censorship is counter-productive even when it
                 does not leak into other areas. For example, it is generally more effective when trying to
                 persuade someone of something to present them with the arguments against it, and then
                 answer those arguments. Unfortunately, preventing people from being aware of the often
                 sophisticated arguments used by racists, makes them vulnerable to those arguments when
                 they do eventually encounter them.
                 Of course the first argument is the stronger one, and would still hold-true even if you didn't
                 accept the second. Basically, you either have censorship, or you don't. There is no

                7. But why is anonymity necessary?

                 You cannot have freedom of speech without the option to remain anonymous. Most
                 censorship is retrospective, it is generally much easier to curtail free speech by punishing
                 those who exercise it afterward, rather than preventing them from doing it in the first place.
                 The only way to prevent this is to remain anonymous. It is a common misconception that
                 you cannot trust anonymous information. This is not necessarily true, using digital
                 signatures people can create a secure anonymous pseudonym which, in time, people can
                 learn to trust. Freenet incorporates a mechanism called "subspaces" to facilitate this.

                8. And what of copyright?

                 Of course much of Freenet's publicity has centered around the issue of copyright, and thus I
                 will speak to it briefly. The core problem with copyright is that enforcement of it requires
                 monitoring of communications, and you cannot be guaranteed free speech if someone is
                 monitoring everything you say. This is important, most people fail to see or address this
                 point when debating the issue of copyright, so let me make it clear:

                     You cannot guarantee freedom of speech and enforce copyright law

                It is for this reason that Freenet, a system designed to protect Freedom of Speech, must
                prevent enforcement of copyright.

                9. But how will artists be rewarded for their work without copyright?

                 Firstly, even if copyright were the only way that artists could be rewarded for their work,
                 then I would contend that freedom is more important than having professional artists (those
                 who claim that we would have no art do not understand creativity: people will always
                 create, it is a compulsion, the only question is whether they can do it for a living).
                 Secondly, it could be questioned whether copyright is effective even now. The music
                 industry is one of the most vocally opposed to enhancements in communication
                 technology, yet according to many of the artists who should be rewarded by copyright, it is
                 failing to do so. Rather it has allowed middle-men to gain control over the mechanisms of
                 distribution, to the detriment of both artists and the public.

                10. Alternatives to Copyright

                 Fortunately it won't come to this. There are many alternative ways to reward artists. The
                 simplest is voluntary payment. This is an extension of the patronage system which was
                 frequently used to reward artists prior to copyright, where a wealthy person would fund an
                 artist to allow them to create full-time. The Internet permits an interesting extension of this
                 idea, where rather than having just one wealthy patron, you could have hundreds of
                 thousands, contributing small amounts of money over the Internet.
                 We actually practice what we preach in this regard too, on the 15th of March 2001 the
                 Freenet Project started taking donations, and within a week we had collected over $1000.

                11. More sophisticated approaches: Fairshare

                 Of course some people ridicule this idea on the basis (I assume) that nobody would ever
                 pay for something unless forced to do so (despite significant evidence to the contrary).
                 While I disagree with their rather depressing outlook on humanity, there are more
                 sophisticated mechanisms which do appeal to people's self-interest, such as "Fairshare",
                 where people can buy in to artists much as a venture capitalist will buy into an idea they
                 like, and if that artist is successful they will be rewarded in proportion to their original
                 contribution. This has the nice effect of encouraging people to give more money to obscure
                 artists who they believe have potential. If their investment doesn't pay-off, then they still
                 have the satisfaction that they contributed to an artist whose work they enjoy.

A Cray SuperComputer Comes to the University of Toronto
                         By Andrew Reeves-Hall

     The Cray X-MP/22 manufactured by Cray Research Incorporated
(CRI) of Minneapolis, Minnesota was delivered and installed at the
U of Toronto this September. The Cray is a well respected computer
- mainly for its extremely fast rate of mathematical floating-point
calculation.  As the university states in its July/August computer
magazine "ComputerNews", the Cray's "level of performance should
enable researchers with large computational requirements at the
university of Toronto and other Ontario universities to compete
effectively against the best in the world in their respective
     The Cray X-MP/22 has two Central Processing Units (CPUs) - the
first '2' in the '22'. The Cray operates at a clock rate of 105 MHz
(the regular, run-of-the-mill IBMPC has a clock rate of 4.77 MHz).
By quick calculations, you would be led to believe the Cray is only
about 20 times faster that the PC. Obviously, this is not the case.
The Cray handles data considerably differently than the PC. The
Cray's circuits permit an array of data (known as a 'vector') to
be processes as a SINGLE entity. So, where the IBMPC may require
several clock cycles to multiply two numbers, the Cray performs
everything in one clock cycle. This power is measured in Millions
of Floating Point Operations Per Second (MFLOPS) - which is to say
the rate at which floating-point operations can be performed. The
Cray MFLOPS vary as it does many activities, but a rate of up to
210 MFLOPS (per CPU) can be achieved.
     The second '2' in the X-MP/22 title refers to the two million
64-bit words (16Mb) of shared central memory. This can be expanded
to four million words in the future if the need arises. But it
doesn't stop there! The Cray can pipe information back and forth
between the CPU memory and the Input/Output Subsystem (IOS). The
IOS then takes it upon itself the store the information in any of
the four storage devices: i) one of the four 1200 Mb disk drives
(at a rate of 5.9Mb every second), ii) one of two standard 200ips
6250bpi tape drives, iii) a Solid State Storage Device (SSD) (which
is much like a 128Mb RAM Disk!), or iv) through to a front-end
computer (the U of T uses both the IBM4381 and a DEC VAX). These
computers would be programmed (usually in FORTRAN) and the
information passed onto the Cray. The results would then be
transfered back to the front end computers.
     The 4 year old Cray was bought used from the California NASA
research centre where it was used in aerodynamic calculations. This
means less cost to buy it and the assurance that it has been 'burned in'.
In case you wanted one for yourself, the U of T was able to purchase
the Cray for the low-low price of $12 million. Over the next five
years, the University predicts the total cost will probably be $25
million when maintenance, staff and other costs are taken into
consideration. To help out, the Ontario Government put in $10 million.
By doing this, all other Ontario University researchers are assured of
access at a reduced cost. By the way, to buy time on the system, it'll
cost you $2000 per hour.  But Ontario researchers only have to pay 7% of
that - $140 per hour. Their first commercial customer is OMNIBUS
Graphics of Toronto who plan to use the Cray in the graphic videos.
If you saw the movie 'The Last Starfighter', you will have already
experienced the graphic capabilites of the Cray (remember the some of
the space scenes!). The Cray did all of the calculations required for
those scenes and let another graphics computer to do the menial task
of drawing the lines and filling with the calculated colour.
     There is so much to talk about when the word 'Cray' pops to mind!
If you are seriously interested in this amazing computer and/or you are
interested in purchasing time on the system, please contact the
people below:
The Centre for Large Scale Computation at the U of T
Llyod Parker, Director
Facilities Manager
Dr. Edmund West
Supercomputer User's Group (for University Researchers, etc)

Computing, Internet & Technology / YouthNet
« on: December 09, 2012, 12:50:29 am »
YouthNet - A Communications network for the
                              Young and Young-at-heart

                YouthNet is an international network that gears itself to
          the interests of the "young and young at heart".  We have echos
          designed to allow young people to talk with other young people
          around the world. The echos covers a wide range of topics from
          entertainment to fantasy to science. Everything from learning how
          to have fun all the way to having fun while learning. Which ever
          your preference may be, there is a place for you in YouthNet.

                But young people around the world are not the only ones
          interested in young people. Many adults are either "young at
          heart" or have serious interest in how the next generation of
          adults are doing. What are they interested in, how are they
          dealing with in today's society, what do they think of where our
          planet is heading? There are many places for these people to talk
          with others like them and even the young people themselves!

                Besides our own forums, we have gateway arrangements with
          both DiscNet and WorldNet. Several echos are passed between these
          networks, giving you greater reach with a single message.
          Messages can be sent person to person within YouthNet and even to
          individuals in these other networks. Many other ideas are
          currently being considered and discussed in the both the sysop
          and coordinators echos. You input to the growth of YouthNet will
          be most welcomed.

                We are a young network ourselves, with coverage in many
          places around the country and in Canada. However there are still
          many cities where we are in need of interested people to serve as
          Coordinators to help our network grow. So even if there isn't a
          YouthNet system in your city, there is no reason why you still
          can join.

                I hope to hear from you soon. Please feel free to contact me
          if you have any questions I may be able to help you with. Later!

                Dan Fitch, Coordinator
               YouthNet/North America (Zone 13)
               (303) 428-2426 BBS

Computing, Internet & Technology / PowerPC processor FAQ
« on: December 09, 2012, 12:49:57 am »
[2-1] What is a PowerPC?

A PowerPC is a microprocessor designed to meet a standard which was
jointly designed by Motorola, IBM, and Apple. The PowerPC standard
specifies a common instruction set architecture (ISA), allowing anyone
to design and fabricate PowerPC processors, which will run the same
code. The PowerPC architecture is based on the IBM POWER architecture,
used in IBM's RS/6000 workstations. Currently IBM and Motorola are
working on PowerPC chips.

The PowerPC architecture specifies both 32-bit and 64-bit data paths.
Early implementations will be 32-bit; future higher-performance
implementations will be 64-bit. A PowerPC has 32 general purpose
(integer) registers (32- or 64-bit) and 32 floating point (IEEE standard
64-bit) registers.

NB: A PowerPC is *not* a computer, any more than an 80486 is a computer.

[2-2] How does PowerPC relate to POWER and POWER2?

As mentioned above, PowerPC is a direct descendant of POWER. POWER2 is
also a descendant of POWER, developed by IBM for use in their
workstations and other systems. POWER2 is an eight-chip multi-chip
module, and was released at approximately the same time as the first
PowerPC chip. While it is faster than the early PowerPC processors, it
is not as fast as the 620 is projected to be. It is likely that IBM will
combine the POWER family into the PowerPC family.

[2-3] What processors have been announced? What are their specs? When
will they be available?

PowerPC 601

    The very first PowerPC. It was designed as a bridge between the
    POWER architecture and the PowerPC architecture. For this reason, it
    incorporates the user-level POWER instructions which were eliminated
    from the PowerPC specification.

PowerPC 601v

    This is a 601, implemented in a 0.5u CMOS 2.5V process. This
    effectively means that it runs faster and draws less power.
    (Originally called the "601+".)

PowerPC 602

    A processor aimed at consumer electronics (set-top boxes, game
    consoles, etc.), PDAs, and embedded controller applications.

PowerPC 603

    A low-power processor, intended for portable applications, e.g.,
    notebook computers. Performance is roughly comparable to the 601
    (see below for benchmarks).

PowerPC 603e

    A higher-performance 603 with a faster clock and bigger caches.
    (Originally called the "603+".)

PowerPC 603ev

    A lower-voltage, faster-clock version of the 603e.

PowerPC 604

    A higher-performance processor, intended for high-end desktop

PowerPC 604e

    A 604 with larger caches.

PowerPC 620

    An even higher-performance processor, aimed at high-end systems and
    multiprocessors. The 620 is the first 64-bit PowerPC implementation.

G3 Series

    The "next generation" of PowerPC processors, expected to ship in

G4 Series

    Expected in 1999.

The 601 is manufactured by IBM and sold by both IBM and Motorola. The
603 and 603e are manufactured by both IBM and Motorola.

Full text:


Many owners of the Apple 15" Multiscan monitor have experienced
problems with sudden and/or erratic changes in the monitor's
colorimetry.  The most common manifestation of this problem is the loss
of the red component, leaving the display blue/green.  Others have
experienced a totally red screen, as well as other odd hues.
Generally, this problem will at first be intermittent, then will
gradually worsen to a 'permanent' state, although sudden permanent
failures are not uncommon.

When my first 15" display went blue, I decided to investigate the
problem myself (being an ardent tinkerer), before allowing myself to
fall prey to the repair industry.  I found, after some poking around,
that the fix was very simple, and have since successfully repaired
dozens of 15" monitors using my slightly unorthodox technique.

In every case I have encountered, the problem has been a loose
connection somewhere on the color board, a 4x5"-ish printed circuit
board attached to the back of the picture tube.  I say somewhere
because it's not always the same connection causing the problem.  These
loose connections were typically the result of a poor soldering job by
the factory.  In some cases there was no solder at all on the errant
connection!  Others would have a very small amount of solder that might
have broken loose from the circuit board from ordinary thermal
expansion/contraction during operation.

My repair procedure consists of the following steps:

1.  Disassembling the monitor.
2.  Locating the problem.
3.  The fix.
4.  Reassembly.

A word of caution:  There is plenty of harmful electricity to be found
in any monitor, especially if it is plugged in, even more especially if
it's turned on.  We're going to do BOTH, so be careful not to touch any
components inside with your bare hands.  Of particular concern is the
ion trap (the big wire coming out of the side of the picture tube) and
the transformer to which it is attached.  As much as 20,000 volts can
be found in this area!  There are also a couple of capacitors nearby
that carry considerable voltage even when the unit is unplugged.
Enough said for now.

Tools needed:  You'll need a Phillips screwdriver, something
non-conductive you can poke around with (a chopstick works well), a
soldering pencil with a reasonably fine point, a de-soldering syringe
(Radio Shack - $2), a small piece of rosin core solder, and something
to release the 2 catches on top of the monitor that hold the back on (I
use an Allen wrench just small enough to fit in the holes).  Also, if
you can't see up close anymore, like me, you'll need your reading
glasses and/or a magnifying glass.


Disassembly:  Turn unit upside down & remove the swivel base by lifting
the locking tab and sliding the base rearward.  Remove the two Phillips
screws on either side of where the swivel base was.  Place unit face
down (screen down).  Use a towel underneath to keep from scratching the
screen.  Using an Allen wrench, ice pick, nail, or anything you can get
in the little square holes behind the top of the bezel (insert about
1"), pry gently outward from the monitor to release the plastic
catches.  This can be a little tricky if you've never done it before.
I usually do one at a time while keeping rearward pressure on the back
half of the cabinet.  Once you've got them free, lift the back of the
cabinet up a few inches, enough so you can reach in and disconnect the
small speaker wire connector from the amplifier circuit board.  This is
easy to spot because it prevents you from fully removing the back.  If
you jerked the back off before you read the last sentence, you're
probably still okay because the connector faces in such a way as it
will pull out without breaking.  Remember where that audio connector is
for reassembly (small board on the side).  Holding the sides of the
bezel, you can ease the monitor back down to rest on its bottom.  A
magazine or newspaper underneath will keep it from scratching your
dining room table,  You are using your dining room table, aren't you?
Now, the area we want to investigate, the color board on the rear of
the picture tube, is enshrouded by a shiny metal shield box.  This
shield is soldered onto the board and must be removed.  Using your
desoldering syringe, heat up and desolder the 5 attaching points.
Nothing particularly delicate of heat sensitive here, although you
don't want to put too much strain on the picture tube connector.  Once
the attachments are desoldered, you should be able to detach the shield
and lift it up off the board.  Leave the ground wires attached to it
and just set it aside.

Investigation:  Situate the monitor so you can work behind it and still
see the picture at the same time, reflected in a mirror (a patio door
or window at night works, too).  Connect your computer to the monitor's
cable, and power everything up.  Keep the kids and pets away!  KEEP
YOUR HANDS AWAY FROM ALL COMPONENTS!  You should now be standing behind
the monitor and seeing your blue/green or red picture reflected in
whatever.  Take your chopstick and begin wiggling the tiny ends of the
components & wires that are poking out of the back of the color board
while watching the reflected picture.  Try to put a little side
pressure on each stub you touch.  You may grasp ONLY the edge of the
color board with your fingers for support.  Be patient!  This can take
a few minutes.  My experience has been if the screen is blue/green, the
bad connection is often in the top right quadrant of the board as you
face the rear of the board (around 2 o'clock).  For red screens, try 9
o'clock.  In time you will find something that miraculously makes your
picture normal every time you touch it.  You have located the problem!

The fix:  Power everything down and put new solder on the connection.
Make sure you get a nice, shiny connection.  Power everything back up,
just to be sure you're okay, which of course you will be.  You might
want to carefully examine the rest of the connections to see if any are
questionable.  It's much easier to check everything while you're in

Reassembly:  Re-attach the metal shielding box to the color board.
Place unit screen-down again on a towel.  lower rear cabinet onto unit
enough so you can re-attach the speaker wire.  Snap cabinet rear into
place, reinstall screws & affix swivel base.

Although this sounds like a big operation, it can actually be done in
less than a half hour.  Try to find a repair shop, though, that will
charge you a half hour's labor to fix it.  HAH!

Finally, good luck with your repair, and let me know how it turns out!

Geary Morton <[email protected]>

Computing, Internet & Technology / Motorola 68040 info
« on: December 09, 2012, 12:47:45 am »
68040 Info:

This new CISC microprocessor
offers RISC performance
Motorola has officially unwrapped its newest 32-bit
microprocessor, the 68040. Manufactured with 0.8-micron
high-speed CMOS technology, the 68040 packs 1.2 million
transistors on a single silicon die. With 900,000 extra
transistors to work with over the 300,000 transistors in a 68000
processor, the 68040's designers added new features and boosted
performance. New features include the following:

-- Optimised 68030 integer unit. While retaining object-code
compatibility with previous 68000-family processors, the IU has
been optimised to execute instructions in fewer clock cycles
(i.e., run faster). The claimed boost in performance is three
times that of a 68030.
-- Integral FPU. The 68020 and 68030 require external FPU
coprocessor chips to handle floating-point math. The 68040,
however, has an FPU built into it, giving it the power to do
serious number crunching. The FPU's data types are compatible
with the ANSI/IEEE 754 standard for binary floating-point math,
and its instruction set is object code-compatible with Motorola's
68881/68882 FPUs. Like the IU, the 68040's on-chip FPU has been
optimised to execute frequently used instructions using fewer
clock cycles. The claimed performance boost is 10 times that of a
-- Large caches. Processor accesses to the system bus are
minimised by storing the most recently used set of instructions
or data in on-chip, 4K-byte caches. Both caches operate
independently but can be accessed at the same time. Bus snoop
logic is used to maintain cache coherence (i.e., it ensures that
the cache's contents match those parts of memory corresponding to
the cache). The bus snooper's design is fine-tuned to support
multiprocessor systems where one or more bus masters or 68040s
might share the same section of memory.
-- Separate memory units for instructions and data. Each memory
unit consists of a memory management unit, a cache controller,
and bus snoop logic. The MMUs use a subset of the 68030's MMU
instruction set. Both memory units function independently of each
other to improve processor throughput.
The 68040 ships with an initial clock speed of 25MHz; higher
speeds are to be available in the future, Motorola says. The
68040 comes in a 179-pin grid-array package. With the elimination
of coprocessor function lines (now that the MMU and FPU are
consolidated onto the processor) and the addition of snoop
control lines, the 68040 is not pin-compatible with the 68030.
Because of the 68040's software compatibility with its
predecessors, it can tap into the existing software base of 680x0
applications. It does this not only while eliminating a component
(the FPU) from a computer's design, but also while improving
performance. In fact, the 68040 executes instructions on the
average of nearly once per clock cycle -- the same as a RISC

Fine-Tuned for Performance
The 68040 was built on the firm foundation of its
predecessors. The design team used the experience garnered from
developing earlier processors to aid in optimising the throughput
of the 040.
The 040 was designed from the ground up, Motorola engineers
said. It incorporates a high degree of parallelism using a number
of internal buses. An internal Harvard architecture gives the
processor full access to both instructions and data. Both the IU
and FPU have separate pipelines and can operate concurrently. For
example, the FPU can perform floating-point instructions
independently of the IU. Each stream (instructions or data) has
its own dedicated cache and MU that function independently of
each other. A smart bus controller assigns priorities to bus
traffic to and from the caches.
There were several key areas where Motorola was able to
boost performance. The first was in reducing the clock cycles
needed to execute certain instructions. The next was to ensure
that the processor funnels instructions and data into itself
quickly and constantly, lest it stall while waiting on
information. The processor then gets its results back into the
system without interfering with incoming information. Finally, as
if this wasn't enough, the processor stays off the system bus to
a greater extent than is the case with other processor designs.
This lets DMA transfers and other bus masters have use of it.

CISC with the Speed of RISC
The IU was optimised so that high-usage instructions execute
in fewer clock cycles, particularly branch instructions. Motorola
said it performed thousands of code traces using real-world
applications to determine which instructions were used most
often. The IU consists of 6 stages: instruction prefetch, decode,
effective address calculation, operand fetch, execution, and
writeback (i.e., the result is written to either a register or to
memory). Each stage works concurrently on the instruction
pipeline. Dual prefetch and decode units deal with the branch
instructions: One set processes the instruction taken on the
branch, and another processes the instruction not taken. In this
way, no matter what the outcome, the IU has the next instruction
decoded and ready to go without seriously disrupting the
pipeline. This complex design has a big pay-off: Motorola has
determined that the average instruction takes 1.3 clock cycles to
execute. The ability to execute an instruction once per clock
cycle is the performance edge of RISC processors -- yet the
68040's IU accomplishes the same goal while executing
complex-instruction-set computer (CISC) instructions.
The FPU adds 11 registers to the 68040 register set: Eight
of them are 80-bit floating-point registers, and three are
status, control, and instruction address registers. The FPU has a
three-stage execution unit, and, like the IU, each stage operates
concurrently. Load and store instructions (FMOVE) can be
performed during other arithmetic operations, and a 64- by 8-bit
hardware multiplication unit speeds many calculations. However,
the FPU only implements a subset of the 68882 instructions
on-chip. The transcendental (trigonometric and exponential)
functions are emulated in software via a software trap. But
Motorola claims that even these instructions should execute 25%
to 100% faster on 25MHz 68040 than on a 33MHz 68882 FPU.

Boosting Throughput
In the area of throughput, each stream is managed by a
separate memory unit that uses an MMU for logical-to-physical
address translations during bus accesses. These MMUs support
demand-paged virtual memory. Both MMUs have a four-way
set-associative address translation cache (ATC) with 4 entries
(versus 22 entries for the 68030). The ATCs reduce processor
overhead by storing the most recent address translations. When an
address translation is required, the ATC is searched, and if it
contains the address, it is used immediately. Otherwise, a
combination of high-speed hardware logic and microcode searches
the translation tables located in main memory.
Like the PU, these MMUs implement a subset of the 68030's
MMU instruction set. Gone are the PLOAD and PMOVE instructions,
because enhanced existing instructions made them superfluous.
Also, only 2 memory page sizes are supported, 4K and 8K bytes,
whereas the 68030 MMU supported 8 page sizes ranging from 256
bytes to 32K bytes. A design tradeoff was made here: A
performance gain was possible by supporting only the 2 most
common page sizes. In any case, this change impacts only
operating-system code, since MMU instructions aren't normally
used by applications.
The two on-chip 4K caches improve processor throughput in 2
ways: They keep the pipelines filled and minimise system bus
accesses. To see how this is done, you must examine the structure
of the cache. Each is a four-way set-associative cache composed
of 64 sets of four lines. A line consists of 4 longwords, or 16
bytes. Cache lines are read or written rapidly using burst-mode
access (a type of bus transfer that moves 16 bytes in a minimum
of clock cycles). For read operations, this fills the cache
efficiently and, at the same time, loads adjacent instructions or
data into the cache that could be used in the near future.

Zen and the Art of Cache Maintenance
As the cache is accessed and data modified, cache-mode bits
in the ATC determine, on a page-by-page basis, the method by
which the information is handled. That is, the ATC entry that
corresponds to the address in main memory whose contents were
copied into the cache decides how the data will be updated. The
modes are cacheable write-through, cacheable copyback,
noncacheable, and noncacheable I/O.
In the cacheable write-through mode, an update to the data
cache forces a write to main memory. While this generates
additional bus activity, this mode is required when working with
a portion of memory that other processors share. The copyback
mode updates the cache line but without updating main memory. The
modified (or "dirty") cache line is copied back into main memory
only when absolutely necessary. "Noncacheable" indicates that the
data shouldn't be cached, which is typically the situation for
shared data structures or for locked accesses (e.g., an operand
access or a translation table entry update). Noncacheable I/O
indicates that the data can't be cached and must be read or
written in the exact order of instruction execution. This mode is
for memory-mapped I/O devices (typically a serial device) where
the information's order is crucial.
The bus snooper is used in multiple bus master situations
where a noncaching bus master, such as a DMA controller, might
modify the memory that is mapped into the 68040's cache. The bus
snooper monitors the external bus and updates the cache as

Cache validity is handled on a line-by-line basis (i.e., a
cache miss triggers a burst-mode access that updates 16 bytes
either in the cache or main memory). The copyback mode minimises
writes to main memory, and the bus controller prioritises each
cache's external memory requests. Read requests take priority
over writes to ensure that the pipelines remain filled.
The caches are critical to the 040's overall throughput.
They keep instructions and data moving into the processor while
satisfying the apparently contradictory role of minimising system
bus accesses. Motorola estimates that the cache hit rate is about
93 percent for instruction and data reads and about 94 percent
for data writes.

A Processor for the 1990's
It is perhaps appropriate that Motorola has introduced the
68040 in the first month of the 1990s. The 040 has the power to
tackle the jobs with large amounts of information that we will be
dealing with regularly in the next ten or so years.
Preliminary results have a 68040 weighing in at 20 million
instructions per second versus the SPARC's 18 MIPS and the
80486's 15 MIPS, all clocked at 25MHz. On floating-point
operations, the 68040 antes up 3.5 million floating-point
operations per second versus the SPARCS's 2.6 MFLOPS and the
80486's 1 MFLOPS. If these numbers are accurate, then the 68040
already out performs one RISC processor.
But the computer industry doesn't stand still. As we move
into the new decade, we can expect new RISC processors to once
again take the lead in performance. Still, the 68040 shows that
owners of CISC systems can have their cake and eat it, too. They
don't have to forsake their software base or settle for mediocre

Computing, Internet & Technology / Nothing computerized is safe
« on: December 09, 2012, 12:43:10 am »
Nothing computerized is safe -- not your Dreamcast, your Palm Pilot, your word processing program or your telephone.  Security is all-inclusive, no longer a realm of obscure networks or sensitive databases full of nuclear codes and credit card numbers.

[Source: HNN]


The realm of computer security is not an isolated slice of life reserved for geeks and bitheads. Security is all-inclusive, no longer a realm of obscure networks or sensitive databases full of nuclear codes and credit card numbers. I know this may be hard to swallow for many people as they haven't given the matter serious thought. Stop reading for a minute and think about all things computerized in your life. Now consider which ones present potential security or privacy concerns to you. If you think any less than 90% or so present these problems, think again.

Some will cast this notion aside in favor of the argument that so many security concerns are so trivial that they make no real difference. Who cares if someone knows you visited a web site or purchased something online -- right? This argument can effectively be countered any number of ways as long as the reader is willing to give them appropriate consideration. First, each of these small concerns add up. To use an old but familiar and fitting analogy, consider each privacy violation a brick. Put enough of these bricks together and you have a full-blown wall. Second, at what point do they stop being small and trivial? If you convince yourself that each security vulnerability is small, they slowly begin to grow without you acknowledging it. Before long, they have turned into full blown risks that your mind associates with 'trivial'.

So in a single day, where do you encounter these risks? Anytime you use technology. Before you say "But I don't use it that much!" think about how much technology surrounds your life. In many cases it has become so integrated that you often stop noticing it. Have a personal organizer like a Palm Pilot? Play games on a Sega Dreamcast? Send e-mail to friends or family via an on-line service? Have controlled access to your office via 'strong' token cards? These points of technology slowly add up and paint a bigger picture of rapidly degrading privacy while security vulnerabilities increase in number. All of the above, and we've barely touched serious computing as far as most people are concerned.

To anyone reading this that is passingly familiar with computer based news outlets like Wired, MSNBC and others, this is no doubt preaching to the choir. For those of you new to the net, I write this in hopes that you are fully aware just how vulnerable your computer setup and system can be. The disturbing trend emerging in people's reactions to security is that perception says if you aren't online, you are safe. I hate to break this to you, but connectivity has little to do with security and privacy. All it takes is a single ten second connection to the net and game over.
You boot up your computer and interface with the Operating System. Be it Windows NT, Windows 95, Solaris or any other platform, it is potentially vulnerable. When you open your browser, it too poses more risks than you can possibly imagine. Both Microsoft Internet Explorer and Netscape Navigator have had their fair share of problems. Even in seemingly safe applications like Microsoft Word lurks danger. Users connecting to the net via cable modem learned quickly that while their walls protected them from neighbor's prying eyes, their modems certainly did not.
As with all articles on security, I try to present the problem and a solution for my readers. What can I possibly suggest to counter such an overwhelming amount of intrusions into your personal privacy and security? Awareness. Just understanding and realizing the concerns better equips you to battle the hoards of bad guys we always read about. Be proactive when using anything electronic, assess the risks, and proceed with caution. All joking aside, it may save you a lot of headache in the near future.

Source for this information:  Safety
Friday, October 29, 1999

Computing, Internet & Technology / Mac Quadra 840AV video
« on: December 09, 2012, 12:42:29 am »
I made a short video showing the style of the Apple Mac Quadra 840AV:

Computing, Internet & Technology / Our 68K Mac software page
« on: December 09, 2012, 12:42:04 am »
I've opened a basic HTML page offering downloadable software for older 68k based Macintosh computers. It features a small portion of our full archive and is made for Macs running older web browsers. The page is available at

The full archive is always available via KDX or Hotline. Use this page to get a copy of the client software.

Art & Graphics / Video camera discussion
« on: December 09, 2012, 12:41:12 am »
Without going broke, I decided to pick up a "prosumer" video camera for my video projects. The camera I chose is a Canon XL2 with both the stock 20x lens and the 3x wide angle lens. This is a standard definition 16:9 (or 4:3) camera using MiniDV tapes. The reason I chose this camera over a smaller HD camera is the control you have over all aspects of the camera. There is room for 3 presets for the standard picture settings, and then you have manual control over the light and gain. It also has XLR ports for an external microphone if you're using it to conduct interviews. The viewscreen is very small so you may want to look into an external screen. I purchased this camera used for about $1300 with extra batteries, a remote, and a light attachment. High definition cameras in this prosumer range usually run over $2500.

Here are some sample videos made with my Canon XL2 camera:

Pages: 1 ... 18 19 [20]