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by johnbeetem
Mon May 28, 2012 4:51 am
Forum: Off topic discussion
Topic: VIA's entry into the low cost computer market
Replies: 102
Views: 19576

Re: VIA's entry into the low cost computer market

And let us face it, Linux is still not user friendly enough (and I say that in spite of having used Unix for 30+ years and I detest Windows). "Unix is user-friendly -- it's just choosy about its friends." Seriously, my own experience with Ubuntu is that it's user-friendly enough. I suspect this is ...
by johnbeetem
Sun May 27, 2012 3:01 pm
Forum: Troubleshooting
Topic: Ethernet chip gets raging hot
Replies: 86
Views: 34918

Re: Ethernet chip gets raging hot

I did buy now some heatsinks ( http://www.zerotherm.net/eng/product/ZH100.asp on amazon for 6.90€ incl. shipping), normally for VGA boards, but two of them fit exactlly onto the CPU and the LAN chip and looking nice also. Thank you for posting this and the pretty picture. I am personally very cauti...
by johnbeetem
Sat May 26, 2012 8:34 pm
Forum: Other programming languages
Topic: Programming the ARM chip
Replies: 134
Views: 49330

Re: Programming the ARM chip

Dave_G_2 wrote:
tufty wrote: IIRC, the SD card access is via a macrocell on the ARM side.
macrocell as in cplds?
My guess:
No, macro cell as in ASIC design, specifically a "hard macro" that Broadcom licenses from the company that designed it. Much more complex than a CPLD macro cell.
by johnbeetem
Fri May 25, 2012 3:13 pm
Forum: C/C++
Topic: Recommeded C++ dev environment ?
Replies: 108
Views: 82127

Re: Recommeded C++ dev environment ?

What they need is: 1. Basic text editor (no code highlighting) 2. Compiler. 3. Assembler. 4. Linker. For learning programming fundamentals, I recommend an interpreter over a Compiler + Assembler + Linker. IMO the assembler and linker layers add unnecessary complexity, and an interpreter can catch r...
by johnbeetem
Wed May 23, 2012 12:33 am
Forum: C/C++
Topic: Recommeded C++ dev environment ?
Replies: 108
Views: 82127

Re: Recommeded C++ dev environment ?

My first C project was built with ed. (see man ed.) But at uni we built our PDP-11 assembler programs with a similar editor which could not go backwards in a file. That concentrates the mind wonderfully. :-D I've experienced both. I really like "ed". Four "man" pages (last time I looked, several de...
by johnbeetem
Tue May 22, 2012 8:57 pm
Forum: Off topic discussion
Topic: VIA's entry into the low cost computer market
Replies: 102
Views: 19576

Re: VIA's entry into the low cost computer market

Looking closely at the photos at apc.io, it does appear that the VIA APC BIOS is socketed -- it looks like an 8-pin SOIC SPI Flash. So you can unbrick it (and maybe hack it) if you have access to a suitable programmer. It may be that only the alpha units are socketed. But it's not hard to remove an ...
by johnbeetem
Tue May 22, 2012 6:31 pm
Forum: General discussion
Topic: The Pi's Chinese rival has arrived
Replies: 78
Views: 24074

Re: The Pi's Chinese rival has arrived

And another... http://www.reghardware.com/2012/05/22/chip_maker_via_outs_49_dollar_raspberry_pi_alike/ from VIA @ $49 and due in July. I'm not up on my ARM nomenclature - what's ARM11 - is that the same as the Pi do I recall? Yes, same ARM1176JZF core as RasPi, except that the WonderMedia (subsidia...
by johnbeetem
Tue May 22, 2012 6:22 pm
Forum: Off topic discussion
Topic: VIA's entry into the low cost computer market
Replies: 102
Views: 19576

Re: VIA's entry into the low cost computer market

Nice board -- convenient having all the connectors on one edge. I checked the WonderMedia site and didn't see any data sheets or user manuals. Not much chance of community involvement without them.
by johnbeetem
Mon May 21, 2012 9:35 pm
Forum: Other programming languages
Topic: Assembly Code
Replies: 60
Views: 21548

Re: Assembly Code

Different strokes and all that. I wonder how much the varying opinions on this subject are related to the specific machine language(s) learned. When I say I love programming in ASM (which I don't actually do that much these days) it's because I wrote most of my ASM code for the PDP-11. The PDP-11 i...
by johnbeetem
Mon May 21, 2012 7:30 pm
Forum: Troubleshooting
Topic: Ethernet chip gets raging hot
Replies: 86
Views: 34918

Re: Ethernet chip gets raging hot

I've just measured my R-Pi temp, which has been on for 5 days CPU = 36.5C Eth Chip = 31.5C HDMI Port = 26.2C Eth Port = 23.4C USB Port = 25.6C SD Card = 34.3C PSU Port = 26.9C Ambient = 21.4C Can you try running a bunch of Ethernet traffic and see what happens to the USB/Ethernet chip? It may use m...
by johnbeetem
Mon May 21, 2012 6:49 pm
Forum: Other programming languages
Topic: Assembly Code
Replies: 60
Views: 21548

Re: Assembly Code

Do people have to know how to manufacture paint or understand its chemical composition to be great artists? Actually, yes. Color pigments are chemicals, and chemicals may react with each other. From what I've read, if you put certain colors together, they react over time and the colors degrade over...
by johnbeetem
Mon May 21, 2012 6:15 pm
Forum: Troubleshooting
Topic: USB Hub wont work and hot board
Replies: 2
Views: 1242

Re: USB Hub wont work and hot board

You might get some ideas from this forum thread: "Ethernet chip gets raging hot".
http://www.raspberrypi.org/phpBB3/viewt ... =28&t=5898
by johnbeetem
Mon May 21, 2012 6:11 pm
Forum: Troubleshooting
Topic: Ethernet chip gets raging hot
Replies: 86
Views: 34918

Re: Ethernet chip gets raging hot

In case this is useful, from another thread. Personally, I'd say a 40 C plastic surface is very warm, but not quite too hot to touch. BTW, IR thermometers are as cheap as $25 now. I measure chip surface temperature in seconds -- specifically, how many seconds I can leave my finger tip on a componen...
by johnbeetem
Mon May 21, 2012 5:58 pm
Forum: Other programming languages
Topic: Assembly Code
Replies: 60
Views: 21548

Re: Assembly Code

Moving swiftly away from the gentlemans flame-war over the virtues of assembly... does anyone know how one would go about manipulating the GPIO from assembly? It would be an interesting exercise to write an LED control program entirely in assembly, if it's possible! Start with the C version from th...
by johnbeetem
Mon May 21, 2012 5:50 pm
Forum: C/C++
Topic: Recommeded C++ dev environment ?
Replies: 108
Views: 82127

Re: Recommeded C++ dev environment ?

I got all the way through university without ever writing a program that consisted of more than one source file. I think I know what you mean, but I have worked professionally with source files over 12K lines each. They were written by other people, of course. I would have imagined those six boxes ...
by johnbeetem
Mon May 21, 2012 3:14 pm
Forum: C/C++
Topic: Recommeded C++ dev environment ?
Replies: 108
Views: 82127

Re: Recommeded C++ dev environment ?

There's no reason Makefiles need to be complex. If a Makefile is complex, IMO it's the fault of its creators and maintainers rather then Make itself, which is very simple in principle though some of its terminology is IMO hard to grok. IDEs can be simple or complex, and it depends entirely on the UI...
by johnbeetem
Sun May 20, 2012 11:50 pm
Forum: C/C++
Topic: Recommeded C++ dev environment ?
Replies: 108
Views: 82127

Re: Recommeded C++ dev environment ?

Here's my favorite IDE story. When I was a university freshman, I took a senior/grad level course called Computer Organization, which included extensive programming on a PDP-11. (Oh bliss! Oh rapture!) The first programming assignment was to write a small PDP-11 ASM program to input a character from...
by johnbeetem
Sun May 20, 2012 3:00 pm
Forum: Troubleshooting
Topic: Network issues - could this really be power issue?
Replies: 25
Views: 6321

Re: Network issues - could this really be power issue?

Another possible reason for the RaspPi misbehaving would be ripple on the power line, so the pressure is not smooth and the water comes out of the tap in bursts. A multimeter would not detect that, it would average the voltage over a second or so. The only way to detect it is to use an oscilloscope...
by johnbeetem
Sun May 20, 2012 2:43 pm
Forum: Troubleshooting
Topic: USB & Ethernet dead
Replies: 79
Views: 40387

Re: USB & Ethernet dead

it turned out that my first guess was right. The 25MHz clock for the LAN9512 was missing. After applying an external clock (using a NI frequency generator), the USB and ethernet worked immediately. Now for the weird part: After removing the external clock source, the crystal now works on its own, e...
by johnbeetem
Sun May 20, 2012 2:31 pm
Forum: Troubleshooting
Topic: Ethernet chip gets raging hot
Replies: 86
Views: 34918

Re: Ethernet chip gets raging hot

Well, these kind of chips do have a metal pad on their underside that should be soldered to the PCB, if for some reason that isn't done the chip cannot dissipate its heat away effectively to the PCB's ground copper plane, it might explain why its getting hot. According to the LAN9512 data sheet, th...
by johnbeetem
Sun May 20, 2012 1:32 am
Forum: Off topic discussion
Topic: New language
Replies: 1
Views: 405

Re: New language

Anything like Valgol (Valley Girl Oriented Language) which brought us the for sure loop and as if statements?
by johnbeetem
Sun May 20, 2012 1:29 am
Forum: Off topic discussion
Topic: ARM Laptops/netbooks
Replies: 7
Views: 2421

Re: ARM Laptops/netbooks

I've been waiting for a good ARM laptop for years, but other than some netbooks and tablets with small screens I haven't seen anything. The picture may change in the next few years according to this article from http://www.eetimes.com/electronics-news/4373279/ARM-aims-to-rise-in-notebook-PC-market :...
by johnbeetem
Sun May 20, 2012 1:09 am
Forum: General discussion
Topic: Forum changes
Replies: 15
Views: 2710

Re: Forum changes

Reading through some of the discussions, I think we may need a forum exclusively for Language Wars. :D I haven't seen a good Language War here for quite a while. They were usually on the Education forum, but now that people are trying to get boards up and succeeding and playing with fun stuff and h...
by johnbeetem
Sat May 19, 2012 6:42 pm
Forum: General discussion
Topic: Forum changes
Replies: 15
Views: 2710

Re: Forum changes

I guess adding all the new categories and sub-categories is a good idea, provided that people bother to post in the appropriate sub-category. We've had a lot of posts in the wrong category when there were only a few of them, so it will be interesting to see what happens when there are many. My first...
by johnbeetem
Sat May 19, 2012 3:48 am
Forum: Troubleshooting
Topic: Bad Solder Job?
Replies: 10
Views: 2803

Re: Bad Solder Job?

From the RasPi schematic, C34 is an AC coupling capacitor for the left audio channel. This prevents a "thump" when you turn on the RasPi with headphones or amplified speakers attached, and prevents burning out the headphone or audio amplifier if the external device is expecting an AC signal (i.e., n...

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