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by jahboater
Wed Jan 23, 2019 2:06 pm
Forum: Troubleshooting
Topic: Enable trim in a SSD or somethin similar
Replies: 2
Views: 74

Re: Enable trim in a SSD or somethin similar

The ext4 mount option "discard" should enable trim.

I don't use it, but instead reduce the SD card writes with a couple of simple changes:
1) Use the ext4 mount option "commit=600" to flush the disk cache every 10 minutes instead of every 5 seconds.
2) Mount /tmp and /var/log as tmpfs
by jahboater
Wed Jan 23, 2019 10:14 am
Forum: Troubleshooting
Topic: bash: cd/var/: No such file or directory
Replies: 1
Views: 49

Re: bash: cd/var/: No such file or directory

emjaay wrote:
Wed Jan 23, 2019 8:17 am
please what can i do i am using raspbian jessie desktop how can i access my var directory
Firstly, you need a space after the cd command.
Secondly, if it is your var directory the path will not start with a /
If it is the system one, then the laading / is fine.
The trailing / is not required.
by jahboater
Wed Jan 23, 2019 8:28 am
Forum: Python
Topic: Learn Python 2 or 3 and how?
Replies: 15
Views: 330

Re: Learn Python 2 or 3 and how?

I see in Gentoo64 on the Pi that "python" starts Python3, and you have to give "python2" to get the old version.

Seems a step in the right direction.
by jahboater
Tue Jan 22, 2019 3:04 pm
Forum: General discussion
Topic: creating bootable sdcard from android tablet
Replies: 3
Views: 86

Re: creating bootable sdcard from android tablet

I am interested to do so because each time I use an sdcard on my desktop through an adapter I destroy the sdcard That's not good. Many millions of people use a desktop PC to write the Raspbian image to an SD card, and the process certainly does not destroy the card. It might be best to understand a...
by jahboater
Tue Jan 22, 2019 10:52 am
Forum: Python
Topic: Learn Python 2 or 3 and how?
Replies: 15
Views: 330

Re: Learn Python 2 or 3 and how?

Heater wrote:
Tue Jan 22, 2019 6:57 am
By an inductive argument, I don't want to waste my time creating things in Python 3 either. Who who knows when that "The intention is to stop supporting and maintaining Python 3" happens.
I doubt they will make the same mistake again ...
by jahboater
Tue Jan 22, 2019 10:49 am
Forum: General discussion
Topic: Raspberry PI for Macbook Pro
Replies: 8
Views: 137

Re: Raspberry PI for Macbook Pro

Yes, and you should connect your Pi to the router, not the Mac.
by jahboater
Tue Jan 22, 2019 10:39 am
Forum: General discussion
Topic: SD Card re instertment
Replies: 2
Views: 63

Re: SD Card re instertment

szkinneman wrote:
Tue Jan 22, 2019 6:31 am
Then I powered it down and took out the sd card.
When you say "powered it down" what did you mean? Did you just turn the power off or unplug it?
Like most full operating systems, it should be shut down cleanly before cutting the power.
by jahboater
Mon Jan 21, 2019 8:11 pm
Forum: General discussion
Topic: Need a case, heatsinks and fan. Also "is this a bad case?"
Replies: 45
Views: 1324

Re: Need a case, heatsinks and fan. Also "is this a bad case?"

I have a 3B that will throttle readily but a modest heat sink secured with Arctic epoxy works well with no slip or slide even with the RPi mounted on its side on a VESA mount at the back of my monitor. Forget about removing it ever unless you are willing to destroy the board. It did not take much.....
by jahboater
Mon Jan 21, 2019 5:25 pm
Forum: Python
Topic: Learn Python 2 or 3 and how?
Replies: 15
Views: 330

Re: Learn Python 2 or 3 and how?

+1

Go with Python 3, it is daft to learn a deprecated early version of the language.

Python is doing well ...
https://www.tiobe.com/tiobe-index/

The current version is 3.7.2
by jahboater
Mon Jan 21, 2019 5:07 pm
Forum: General discussion
Topic: Need a case, heatsinks and fan. Also "is this a bad case?"
Replies: 45
Views: 1324

Re: Need a case, heatsinks and fan. Also "is this a bad case?"

Indeed, Although Noctua fans are good, at 4500 rpm it cannot be quiet .... It actually is quiet. Spec's linked in post above. Noctua fans are pretty awesome, but not cheap. That fan cost almost half what the Pi 3B+ cost (although I already had it from a previous system). Wow "Acoustical noise 17,9 ...
by jahboater
Mon Jan 21, 2019 4:17 pm
Forum: General discussion
Topic: Unclear on throttling
Replies: 9
Views: 162

Re: Unclear on throttling

Breaching the "soft temp" limit will cause a throttle down from 1.4GHz to 1.2GHz.
This happens by default at 60C which is easily reached for a poorly cooled Pi3B+.

Set this in /boot/config.txt to raise the threshold:

temp_soft_limit=70

and/or improve the cooling.
by jahboater
Mon Jan 21, 2019 10:46 am
Forum: General discussion
Topic: STICKY: Making your own custom burn-n-boot Raspbian image
Replies: 10
Views: 384

Re: Making your own custom burn-n-boot Raspbian image

Helpful posts HawaiianPi and Sakaki, thanks.
Should be in a sticky!
by jahboater
Mon Jan 21, 2019 9:26 am
Forum: General discussion
Topic: Need a case, heatsinks and fan. Also "is this a bad case?"
Replies: 45
Views: 1324

Re: Need a case, heatsinks and fan. Also "is this a bad case?"

Indeed, Although Noctua fans are good, at 4500 rpm it cannot be quiet .... My last Intel PC had a fan, as usual it was mounted directly on the large heatsink. After a few months it started throttling badly. Eventually I realized the heatsink fins were clogged with dust and it was no longer working. ...
by jahboater
Sun Jan 20, 2019 2:34 pm
Forum: Off topic discussion
Topic: Why Avoid BASIC on RPi?
Replies: 1292
Views: 41427

Re: Why Avoid BASIC on RPi?

Heater wrote:
Sun Jan 20, 2019 9:47 am
It has taken me two or three weeks now to find out what this chip is!
Try:

Code: Select all

gcc -march=native -Q --help=target | grep arch
also

Code: Select all

gcc -march=native -S -fverbose-asm fibo.c -o fibo.s
grep arch fibo.s
by jahboater
Sun Jan 20, 2019 10:14 am
Forum: C/C++
Topic: C++ IDE
Replies: 40
Views: 4643

Re: C++ IDE

There is a new TIOBE Index for January 2019 and it has an interesting summary of changes over the last year:

https://www.tiobe.com/tiobe-index/

TIOBE a well known measure of the popularity of different languages.
by jahboater
Sun Jan 20, 2019 8:53 am
Forum: Off topic discussion
Topic: Why Avoid BASIC on RPi?
Replies: 1292
Views: 41427

Re: Why Avoid BASIC on RPi?

Anyway -march=sandybridge makes no noticeable difference. GCC's CPU detection on Intel has worked for a long time (unlike on ARM). Probably because there is a decent CPUID instruction which gives exact and exhaustive details of every modern processor. According to "man GCC" it even goes as far ahea...
by jahboater
Sun Jan 20, 2019 8:00 am
Forum: Off topic discussion
Topic: Why Avoid BASIC on RPi?
Replies: 1292
Views: 41427

Re: Why Avoid BASIC on RPi?

I have no idea what dumb ass name Intel gave to my actual CPU, a Core i7. See /proc/cpuinfo:- $ grep Intel /proc/cpuinfo vendor_id : GenuineIntel model name : Intel(R) Core(TM) i7-3770K CPU @ 3.50GHz vendor_id : GenuineIntel model name : Intel(R) Core(TM) i7-3770K CPU @ 3.50GHz vendor_id : GenuineI...
by jahboater
Sun Jan 20, 2019 1:01 am
Forum: General discussion
Topic: Need a case, heatsinks and fan. Also "is this a bad case?"
Replies: 45
Views: 1324

Re: Need a case, heatsinks and fan. Also "is this a bad case?"

I'd like to ask how can I run temperature/stress tests on Raspbian after I'm fully set up, Run this for an hour or so, it will get your CPU temp up faster than anything else:- wget https://raw.githubusercontent.com/ssvb/cpuburn-arm/master/cpuburn-a53.S gcc -o cpuburn-a53 cpuburn-a53.S ./cpuburn-a53...
by jahboater
Sat Jan 19, 2019 4:09 pm
Forum: Troubleshooting
Topic: Any reason why a Pi 3 will not run from a 64 GB card?
Replies: 15
Views: 343

Re: Any reason why a Pi 3 will not run from a 64 GB card?

Yes, I have never had any problems with any Sandisk or Samsung cards. The A1 or A2 app class are designed for the fast random 4k reads - ideal for the Pi. Older cards were designed for cameras and media where fast sequential performance is required. These have just appeared on the market (the extrem...
by jahboater
Sat Jan 19, 2019 7:55 am
Forum: Troubleshooting
Topic: Any reason why a Pi 3 will not run from a 64 GB card?
Replies: 15
Views: 343

Re: Any reason why a Pi 3 will not run from a 64 GB card?

As I posted, the card reports errors unrelated to its use in the Pi. As long as a Pi will work with a 64 GB card I will try another. I am hoping someone can provide some experience good or bad. Yes, the Pi works fine on larger cards (the ext4 file system it uses supports any disk size for the fores...
by jahboater
Sat Jan 19, 2019 7:43 am
Forum: Off topic discussion
Topic: Why Avoid BASIC on RPi?
Replies: 1292
Views: 41427

Re: Why Avoid BASIC on RPi?

Oops. I was under the impression that volatile was not part of ANSI/C89 standard. I guess it is, so never mind. Is it possible FreeBasic originally targeted a K&R style C compiler as the code generator? Ah yes, volatile was introduced in C89. I've just found a scanned archive of the 1st edition of ...
by jahboater
Fri Jan 18, 2019 8:48 am
Forum: Beginners
Topic: first app on pi, can't decide on language
Replies: 3
Views: 129

Re: first app on pi, can't decide on language

I can probably get more Forum support if I go with python. But I got to say, it feels weird to me. I can see the lure, no declaring variables, no keeping track of what variable is what type. No semicolons to miss. But the same time indenting is of extreme importance. And while the thorny ID will al...
by jahboater
Thu Jan 17, 2019 10:10 am
Forum: General discussion
Topic: RISC-V
Replies: 89
Views: 2915

Re: RISC-V

For the Raspberry Pi3B+ .... 132 bytes? Ha ha, beats my Free Pascal version which was about 1MB ;) I might brush up on my C coding ;) Now down to 124 bytes :) .global _start _start: mov r0,#1 adr r1,message mov r2,#12 mov r7,#4 svc 0 // write mov r7,#1 svc 0 // exit message: .ascii "Hello world\n" ...
by jahboater
Thu Jan 17, 2019 9:33 am
Forum: Troubleshooting
Topic: RASPBIAN : commands from bashrc not starting on boot
Replies: 3
Views: 60

Re: RASPBIAN : commands from bashrc not starting on boot

Try /etc/rc.local instead of .bashrc
by jahboater
Thu Jan 17, 2019 9:09 am
Forum: General discussion
Topic: RISC-V
Replies: 89
Views: 2915

Re: RISC-V

Gavinmc42 wrote:
Thu Jan 17, 2019 5:23 am
What is smallest "hello world" code for various compilers/languages?
For the Raspberry Pi3B+ ... 128 bytes?

Code: Select all

$ ls -l hello
-rwxr-xr-x 1 pi pi 128 Jan 17 10:04 hello
$ file hello
hello: ELF 32-bit LSB executable, ARM, EABI5 version 1 (SYSV), statically linked, stripped
$ ./hello
Hello world

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