Slashdot Mirror

Level designers don't like radiosity lighting? Well, here's one who loves it. I've been doing some level design for Half-Life and I must admit that radiosity lighting is probably one of my favourite features. It makes ultra-realistic lighting embarrasingly easy to do.

I don't know what these claims of 'fuzzy shadows' are about - I get nice, sharp shadows where I want them, and diffuse shadows where I want them. And simulated diffuse reflections off floors, light underneath tables, light going round corners, indirect lighting, smoothed lighting around 'curved' objects... And all by placing a couple of light textures in relevant places.

I'm amazed that radiosity lighting was dropped from Quake 3. The poor lighting in Quake was one of my least favourite features (simulating radiosity lighting with multiple light entities wasn't fun, and no inverse-square was a joke).

Oh well... Time to wait for Team Fortress 2 and Half-Life 2. :-)

Ford Prefect

No mention of 'Baby' either, the world's first stored-program computer, a working replica of which was completed at the end of '98 on its 50th anniversary. Check here for more details.

here

I doubt anyone will read this, but who cares...

I've been experimenting with very basic colour support, using a kind of look-up table. The program has a list of ANSI foreground and background colours, along with various characters to print, and roughly what RGB values they correspond to. It's very messy, and doesn't work too well, but the colour is vaguely acceptable...

You can see some really bad screenshots here, here, here, and here - the first two were of the initial, really bad colour support, being developed over telnet, naturally... The third is the new colour support with a very small lookup table, and the third is with a slightly larger lookup table (still very small though).

I considered 'detail' support, but I'm a terrible programmer and it probably wouldn't be worth the effort.

I've also got the program to display frames in sequence - it's almost semi-watchable... :-)

Ford Prefect

I doubt anyone will read this, but who cares...

I've been experimenting with very basic colour support, using a kind of look-up table. The program has a list of ANSI foreground and background colours, along with various characters to print, and roughly what RGB values they correspond to. It's very messy, and doesn't work too well, but the colour is vaguely acceptable...

You can see some really bad screenshots here, here, here, and here - the first two were of the initial, really bad colour support, being developed over telnet, naturally... The third is the new colour support with a very small lookup table, and the third is with a slightly larger lookup table (still very small though).

I considered 'detail' support, but I'm a terrible programmer and it probably wouldn't be worth the effort.

I've also got the program to display frames in sequence - it's almost semi-watchable... :-)

Ford Prefect

I doubt anyone will read this, but who cares...

I've been experimenting with very basic colour support, using a kind of look-up table. The program has a list of ANSI foreground and background colours, along with various characters to print, and roughly what RGB values they correspond to. It's very messy, and doesn't work too well, but the colour is vaguely acceptable...

You can see some really bad screenshots here, here, here, and here - the first two were of the initial, really bad colour support, being developed over telnet, naturally... The third is the new colour support with a very small lookup table, and the third is with a slightly larger lookup table (still very small though).

I considered 'detail' support, but I'm a terrible programmer and it probably wouldn't be worth the effort.

I've also got the program to display frames in sequence - it's almost semi-watchable... :-)

Ford Prefect

I doubt anyone will read this, but who cares...

I've been experimenting with very basic colour support, using a kind of look-up table. The program has a list of ANSI foreground and background colours, along with various characters to print, and roughly what RGB values they correspond to. It's very messy, and doesn't work too well, but the colour is vaguely acceptable...

You can see some really bad screenshots here, here, here, and here - the first two were of the initial, really bad colour support, being developed over telnet, naturally... The third is the new colour support with a very small lookup table, and the third is with a slightly larger lookup table (still very small though).

I considered 'detail' support, but I'm a terrible programmer and it probably wouldn't be worth the effort.

I've also got the program to display frames in sequence - it's almost semi-watchable... :-)

Ford Prefect

I swear that second one looks like Peter Davidson... scary stuff.
--

I must confess, I was the person who thought this whole thing up. I'm really very, very sorry about it.

I'm a terrible programmer, but in half an hour of mucking about I came up with something interesting. There's some very crude screenshots here and here. I'm currently working on some working scaling code (to get the aspect ratio right), 'aliasing' (,,, ''' etc), and possibly some way for the program to do the grabbing itself. Image grabbing is currently done by Xawtv's streamer program.

Well, as I said, I'm very sorry about all this.

I must confess, I was the person who thought this whole thing up. I'm really very, very sorry about it.

I'm a terrible programmer, but in half an hour of mucking about I came up with something interesting. There's some very crude screenshots here and here. I'm currently working on some working scaling code (to get the aspect ratio right), 'aliasing' (,,, ''' etc), and possibly some way for the program to do the grabbing itself. Image grabbing is currently done by Xawtv's streamer program.

Well, as I said, I'm very sorry about all this.

Here's a link to some work on Asynchronous processors at the University of Manchester, UK
(Place where the first computer was built 51 years ago)
Really cool stuff ;)
Amulet Processors

Here's a link to some work on Asynchronous processors at the University of Manchester, UK
(Place where the first computer was built 51 years ago)
Really cool stuff ;)
Amulet Processors

This was probably quite difficult to implement, but isn't exactly conceptually brilliant. Modern computers already run at different clock rates internally. Your disk I/O bus runs at one speed, your video processor runs at another speed and the CPU still spends a lot of time waiting for stuff to come down the system bus from memory.

It's even less conceptually brilliant, when you see what people elsewhere have been working on - namely wavepipelined architectures.

Funny... people just keep on reinventing the wheel... fire... and then they patent it to hell.

IIRC, the guys at Manchester University were working on this back in 1989/1990 (or at least they were when I went on a tour of the place...). Back then, it was just called the "wave pipelined RISC chip" - these days, it's the "Amulet". Check it out. It's based on ye olde ARM processor architecture - but the implementation is completely asynchronous -- that is, each individual logic element is clocked separately.

Sure, it's still experimental... sure, it's slower than other chips - but it also predates IBM's announcement by about 11 years. Just goes to show - academia ain't entirely useless ;-)

Links
Architectural Overview at Berkeley

The Amulet Asynchronous Logic Group at Manchester University

Who needs clocks? Bah!

Simon

This was probably quite difficult to implement, but isn't exactly conceptually brilliant. Modern computers already run at different clock rates internally. Your disk I/O bus runs at one speed, your video processor runs at another speed and the CPU still spends a lot of time waiting for stuff to come down the system bus from memory.

It's even less conceptually brilliant, when you see what people elsewhere have been working on - namely wavepipelined architectures.

Funny... people just keep on reinventing the wheel... fire... and then they patent it to hell.

IIRC, the guys at Manchester University were working on this back in 1989/1990 (or at least they were when I went on a tour of the place...). Back then, it was just called the "wave pipelined RISC chip" - these days, it's the "Amulet". Check it out. It's based on ye olde ARM processor architecture - but the implementation is completely asynchronous -- that is, each individual logic element is clocked separately.

Sure, it's still experimental... sure, it's slower than other chips - but it also predates IBM's announcement by about 11 years. Just goes to show - academia ain't entirely useless ;-)

Links
Architectural Overview at Berkeley

The Amulet Asynchronous Logic Group at Manchester University

Who needs clocks? Bah!

Simon

• Obfuscated FoxPro
• Obfuscated Java Programming Contest
• The 1st Annual Obfuscated Perl Contest
• Obfuscated PostScript Contest

Asynchronous logic uses no clock. Supposedly a StrongARM CPU has been fabbed based on an asynchronous design but is not yet available commercially. It may be the case that the Crusoe is the first commercial CPU based on asynchronous logic. For more information check out the asynchronous logic Home Page.

Asynchronous logic uses no clock. Supposedly a StrongARM CPU has been fabbed based on an asynchronous design but is not yet available commercially. It may be the case that the Crusoe is the first commercial CPU based on asynchronous logic. For more information check out the asynchronous logic Home Page.

Just out of interest, what's your opinion of Maverik

There are already asynchronous chips. University of Manchester developed the Amulet2e, a ARM7 derivate, from 1993 to 1995. It is compatible to ARM-v4G instruction set.

Comparison data (I wish I could use tables):

CPU: ARM 710 -- Amulet2e fab process: 600nm -- 500nm transistor count: 570,000 -- 454,000 cache size: 8kB -- 4kB speed: 23 MIPS -- 38 MIPS

Even though the cache is only half as big it's faster.

Another one is the TITAC-2 developed in Japan. It is based on the MIPS R2000 but is not binary compatible.

Comparison for that:

CPU: TITAC-2 -- MIPS R2000 transistor count: 496,000 -- 100,000 core voltage: 3.3V -- 5V power consumption / w/o cache: 2.11W / 1.02W -- - / 2W performance / w/o cache: 54.1 MIPS / 26.5 MIPS -- - / 12 MIPS

The TITAC-2 worked with 1.5V to 6V in environment temperatures of -196C to 100C (-320F to 212F, if I calculated correctly).

Clocked chips have to be clocked slow enough for the worst case (a set of commands that take a really long time before the chip enters a stable state), that's why overclocked / overheated CPUs work fine most of the time but only sometimes crash. These async CPUs get faster when they get cooler. They always run as fast as is possible given the temparature and commands to execute.

Rumors tell that German company Hagenuk will employ the Amulet3 in commercial products this year.

If you want to know more about micro pipelines, null convention logic and dual rail encoding, look it up in c't 17/99 (if you have that issue or want to reorder it and can read German of course ;-)

The Amulet is not a StrongARM chip it is a processor that impliments the same instruction set as the ARM7 processor. Its goal is to achieve extremely high power efficency not primarily speed.

The main advantage of the asynchronous logic is the _very_ low power disipation when idle this is effectively zero. A lot better than the StrongARM design when idle which due to the compromises necessary for higher speeds leaks a subtantial amount of current. Also due to the asynchronous logic not all parts of the need to be running at all times, these logic cuicits do not need power when not in use so there is even less power drain.

There is another advantage and that is RF emmisions, without a clock there are no high level harmonics in the amulet core making it a very quiet chip.

LES..

Okay, the reason I put the word "allegedly" into my story quote is because I expected there to be some considerable disagreement about which was the "first" computer. Particularly since Germany, France, the UK and the USA all claim this honour (plus a few others I expect).

The problem is: what is a computer? Do you mean a calculator? So does an abacus count? Something that runs a program? So does a weaving loom count? Something electronic that runs a program? So does a washing machine count? Something digital? Something that has a modifyable program? Something that stores its program in the same way as its data?

As you can see, there are many definitions of "computer". Stop bickering!

And to add to that, early computers were often an international effort. Certianly Bletchley Park relied heavily on US involvement towards the end of the war.

That doesn't detract from the fact that Bletchley Park was a major contributor to both cryptography and modern computing.

Anyway, here's a few more British historical computing links for those who like nostaligia. If anyone would like to add some links to sites about other historical computers- of any nation- I'd be most interested.

Colossus I
The LEO - Lyons Electric Office (my dad worked on this)
The WITCH (my dad worked on this, too!)
The Baby

--

While this DX is quite different ( and more powerful), people might be interested to know about other Open Source visualisation software :

The General Mesh Viewer:

www-xdiv.lanl.gov/XCM/gmv/GMVHome.htm l

Maverik:

aig.cs.man.ac.uk/systems/Maverik/

In fact I've read a couple of academic papers on this very topic. Here is one dealing with the decision making process for creative bookkeeping. And I'll have to bug Prof. Zeckhauser to get his recent publication on "Earnings Manipulation to Exceed Thresholds" on-line. It's a refreshing piece of data from real companies on earnings manipulations to meet the bright lines of Wall St. earnings expectations and earnings manipulations for private companies just prior to IPO.
And don't expect an external accounting firm to find discrepancies during an audit. They aren't hired to work that way. If BCCI (the Bank of Crooks and Criminals International) could undergo audits from one of the Big 5 and come out clean until a post-mortem, I'm sure that Microsoft could as well.