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by jahboater
Mon Dec 09, 2019 7:22 pm
Forum: General discussion
Topic: How does the Raspberry Pi work?
Replies: 17
Views: 279

Re: How does the Raspberry Pi work?

It would likely be wise to leave out any discussion of magic from the report turned in for grading. Well, I think its magic that you can get a highly capable and usable computer that's the size of a credit card and costs $35 :) Or perhaps in the OP's case, technology that is sufficiently far advanc...
by jahboater
Mon Dec 09, 2019 7:11 pm
Forum: General discussion
Topic: How does the Raspberry Pi work?
Replies: 17
Views: 279

Re: How does the Raspberry Pi work?

youngdawg wrote:
Mon Dec 09, 2019 5:55 pm
How does the Raspberry Pi work?
Like any other computer.
by jahboater
Mon Dec 09, 2019 3:08 pm
Forum: Gentoo
Topic: ntfs problem
Replies: 11
Views: 150

Re: ntfs problem

gkaiseril wrote:
Mon Dec 09, 2019 3:04 pm
"apt-get" is the command to update and upgrade raspbian, so I find it hard to believe it does not work.
This is gentoo not debian.
by jahboater
Mon Dec 09, 2019 11:34 am
Forum: General discussion
Topic: Pi3 sd card
Replies: 10
Views: 168

Re: Pi3 sd card

Affleck001 wrote:
Mon Dec 09, 2019 11:27 am
Thank you for the reply, after having read this guide i am thinking i may have a bad sd card. What i was looking at was burning a 128gb front end image on to an sd card
Not sure what that means, but I suspect you will have problems trying to write 128GB to a 128GB card.
Perhaps try a 256GB card.
by jahboater
Mon Dec 09, 2019 11:31 am
Forum: General discussion
Topic: Pi3 sd card
Replies: 10
Views: 168

Re: Pi3 sd card

Maximum is at least 64GB, probably loads higher but I have never tried anything bigger than that, but i am sure others have. There may be some physical limitation that I don't know of, but the ext4 filesystem that Raspbian uses has no practical limit (actually its 1EB which I think is 1,000,000,000...
by jahboater
Sun Dec 08, 2019 9:33 am
Forum: C/C++
Topic: From python to C/C++
Replies: 5
Views: 162

Re: From python to C/C++

But how to I do the same thing in C/C++?? Which language you mean? In C you might use scanf (and for output printf) which have powerful formatting. These are available in C++ too, but (as noted above) C++ also has the rather cool cin/cout and the << >> overloads. In both languages there are many op...
by jahboater
Sat Dec 07, 2019 11:15 pm
Forum: Python
Topic: Replacement for Arduino "int" command.
Replies: 2
Views: 59

Re: Replacement for Arduino "int" command.

Python is dynamically typed:

Code: Select all

eastSNSR = 0
should suffice.

By the way, "int" is not a command.
For a statically typed language like C, it tells the compiler what type of variable eastSNSR is (an integer in this case).
Python on the other hand will work the type out for itself.
by jahboater
Sat Dec 07, 2019 4:29 pm
Forum: Troubleshooting
Topic: Installing x86 on ARM
Replies: 17
Views: 357

Re: Installing x86 on ARM

LC_ALL is C by default anyway.
by jahboater
Sat Dec 07, 2019 1:32 pm
Forum: Bare metal, Assembly language
Topic: [Solved] System calls
Replies: 9
Views: 210

Re: System calls

Somewhat related; I'm building my ARM userland assembly programs with 'as' and 'gcc' (arm-linux-gnueabihf) using - as -o test.o test.s gcc -o test test.o And, without specifying or #including any explicit libraries that allows me to include "bl printf" in my assembly source which produces output in...
by jahboater
Sat Dec 07, 2019 10:42 am
Forum: Other programming languages
Topic: Dart Native on Raspberry Pi
Replies: 14
Views: 530

Re: Dart Native on Raspberry Pi

I make that about 10 times slower than C or Rust on a Pi 3B: I bet the C version (and probably the rust version) are smaller than 6.2MB too! Edit: In fact on my PC, the C version takes: $ filefrag -v fibo Filesystem type is: ef53 File size of fibo is 4312 (2 blocks of 4096 bytes) ext: logical_offse...
by jahboater
Sat Dec 07, 2019 8:05 am
Forum: Bare metal, Assembly language
Topic: [Solved] System calls
Replies: 9
Views: 210

Re: System calls

If you look in /usr/include/arm-linux-gnueabihf/asm/unistd-common.h you'll see all the C #defines (well most, there are a few extra in unistd.h) naming the syscalls for ARM. Presumably thats what #include <sys/syscall.h> resolves to? You can create a stub program and use the gcc options: gcc -E -dM...
by jahboater
Fri Dec 06, 2019 5:54 pm
Forum: Troubleshooting
Topic: Pi4 firmware and teething issues
Replies: 6
Views: 244

Re: Pi4 firmware and teething issues

I've always been a bit unsure of this...if I'm running buster lite, does full-upgrade or other alternatives (i.e., other than "update/upgrade") add the non-lite packages? I don't want to end up having a full buster image...just looking for some clarification. Thanks in advance. No. The upgrade inst...
by jahboater
Fri Dec 06, 2019 7:49 am
Forum: General discussion
Topic: open file in idle or other text editor over ssh from linux
Replies: 6
Views: 152

Re: open file in idle or other text editor over ssh from linux

use any normal text based editor, for example:

nano file.py

vi file.py

emacs file.py

ed file.py

there are many others.
by jahboater
Thu Dec 05, 2019 4:13 pm
Forum: C/C++
Topic: Use of system timers
Replies: 8
Views: 179

Re: Use of system timers

I don't quite understand - is clock_gettime mapped to the system timer on the kernel level? I think so for CLOCK_MONOTONIC_RAW (but not for CLOCK_REALTIME of course). From "man clock_gettime" see: CLOCK_MONOTONIC_RAW (since Linux 2.6.28; Linux-specific) Similar to CLOCK_MONOTONIC, but provides acce...
by jahboater
Wed Dec 04, 2019 10:46 pm
Forum: General programming discussion
Topic: Tatami Pi Fun.
Replies: 165
Views: 4556

Re: Tatami Pi Fun.

Heater wrote:
Wed Dec 04, 2019 10:39 pm
Turns out I forgot to remove the array bounds checking in Rust. Sometimes you just have to take the safety wheels off.
I thought that was Rust's raison d'être ?
Seems a shame to make it all unsafe and be as bad as C.
by jahboater
Wed Dec 04, 2019 8:04 pm
Forum: General discussion
Topic: Limit frequency of the Pi: USB/Ethernet performance affected?
Replies: 7
Views: 289

Re: Limit frequency of the Pi: USB/Ethernet performance affected?

My experience is the 4B runs without heat-related throttling when mounted vertically with plenty of free airflow above and below the circuit board. For example, one could mount the bare circuit board to the back of a monitor or television using standoffs and likely never have any heat-related probl...
by jahboater
Wed Dec 04, 2019 11:07 am
Forum: General discussion
Topic: Raspberry Pi 4 is not a replacement for a real PC, (as it doesn't have Skype) sorry!
Replies: 72
Views: 2547

Re: Raspberry Pi 4 is not a replacement for a real PC, (as it doesn't have Skype) sorry!

diogen151 wrote:
Wed Dec 04, 2019 10:48 am
Skype does not determine whether a computer is a desktop PC or not
Yes, agreed, nonsense.

All OS's have tools that others don't have, and all OS's are missing some tools.

Windows lacks countless programs that Linux has as standard, and yet no one would suggest its not a desktop OS.

Crazy thread.
by jahboater
Wed Dec 04, 2019 10:58 am
Forum: Beginners
Topic: cant open config from Raspi command line.
Replies: 6
Views: 168

Re: cant open config from Raspi command line.

You could put:

Code: Select all

export TERM=xterm 
in ~/.bashrc

:) Or you could use :)

Code: Select all

sudo ed /boot/config.txt
"ed" does not require TERM to be set.
:)

Incidentally you can type:

nano /boot/con<TAB> and it will complete the name for you (saves time if you often edit the file).
by jahboater
Tue Dec 03, 2019 5:02 pm
Forum: C/C++
Topic: Where can I begin learning C/C++?
Replies: 72
Views: 5824

Re: Where can I begin learning C/C++?

rather than the correct int main() Don't you need "int main( void )" to be correct? One thing missing from the present thread on learning C is how important it is to choose a suitable programming project to motivate the learning. In my opinion, only by writing code is it possible to learn any kind ...
by jahboater
Mon Dec 02, 2019 8:16 pm
Forum: Bare metal, Assembly language
Topic: What can i really make in ARM Assembly
Replies: 18
Views: 1750

Re: What can i really make in ARM Assembly

dwelch67, and thats just the elementary part of the syntax, then there is the garbage you need and need to master per toolchain/version of the extra stuff to tell the compiler how to connect to and use that assembly. I don't know where you got all that from? You certainly don't need any of it with G...
by jahboater
Mon Dec 02, 2019 11:16 am
Forum: Raspbian
Topic: What's the advantage of Raspbian over other distros for pi 4?
Replies: 7
Views: 374

Re: What's the advantage of Raspbian over other distros for pi 4?

Raspbian is recommended for the reasons above, its well supported and reliable, a great distro. However, to avoid supporting two distro's, Raspbian is built for the old Pi1 or Pi Zero ARMv6 architecture (the current model is Cortex-A72). There is now a 64-bit kernel in testing, but the user land rem...
by jahboater
Sun Dec 01, 2019 5:51 pm
Forum: General programming discussion
Topic: Tatami Pi Fun.
Replies: 165
Views: 4556

Re: Tatami Pi Fun.

jcyr wrote:
Sun Dec 01, 2019 5:02 pm
Rust written OS only a few months away

https://www.theregister.co.uk/2019/11/2 ... lfhosting/
I'll be impressed if Redox has absolutely no "unsafe" sections and is written entirely in Rust.
by jahboater
Sun Dec 01, 2019 12:40 pm
Forum: General discussion
Topic: SD Card Capacity
Replies: 4
Views: 207

Re: SD Card Capacity

Or forget noobs and just install the Raspbian image directly. Then there is no need to format the SD card or delete any partitions at all (and you will gain some space etc). The Raspbian image is a complete raw disk image including the partition table. Get it from here, and follow the instructions: ...
by jahboater
Sun Dec 01, 2019 10:59 am
Forum: Bare metal, Assembly language
Topic: What can i really make in ARM Assembly
Replies: 18
Views: 1750

Re: What can i really make in ARM Assembly

There's no "rbit" instruction on my S/370 processor. That's fine, there isn't on my Intel PC either, but the code compiles cleanly and works perfectly - as it would do on the S/370 of course. It will just run faster on aarch64. Never use inline assembly without providing a portable alternative that...

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