Re: [vcf-midatlantic] Monitor needed for museum
Hey look! http://www.robotshop.com/en/raspberry-pi-vga-adapter.html Ethan Dicks (VCF East frequent PDP-8 exhibitor) turned me on to this. He teaches Pi classes at his local hackerspace. He said that in his experience the Pi usually "just works" to detect the video type, but that it's more reliable when you edit the config file. For 7 bucks I am definitely buying us one. I already have a low-profile widescreen VGA LCD at home that's the perfect size for our application. (VCF's existing supply of VGA LCDs are all square-shaped.) All's well that ends well.
If one needs to fiddle a config file to get composite video out, then that would be a show stopper for fixing the pi. I await test results. Bill This email is free of malware because I run Linux. On Tue, Aug 22, 2017 at 1:19 AM, Evan Koblentz via vcf-midatlantic < vcf-midatlantic@lists.vintagecomputerfederation.org> wrote:
Hey look!
http://www.robotshop.com/en/raspberry-pi-vga-adapter.html
Ethan Dicks (VCF East frequent PDP-8 exhibitor) turned me on to this.
He teaches Pi classes at his local hackerspace. He said that in his experience the Pi usually "just works" to detect the video type, but that it's more reliable when you edit the config file.
For 7 bucks I am definitely buying us one.
I already have a low-profile widescreen VGA LCD at home that's the perfect size for our application. (VCF's existing supply of VGA LCDs are all square-shaped.)
All's well that ends well.
On 8/22/2017 9:37 AM, William Dudley via vcf-midatlantic wrote:
If one needs to fiddle a config file to get composite video out, then that would be a show stopper for fixing the pi.
I await test results.
Bill I realize that I may be missing some of the points in this chicken vs. egg scenario I have been somewhat following but the config.txt file being located in the root directory of the micro SD card is editable using a card reader & MicroSD to SD adapter on a windows or Mac computer. I had to do that when I couldn't get a Pi to display on a finicky monitor once. I realize that I am one of the least knowledgeable people here regarding this stuff but I mention this in case it was overlooked in the fray. Regards, Jeff
OH MY GOD. I CANNOT TAKE THIS ANYMORE. After 25 messages and three days, two problems that any reasonable person would have solved in about five minutes remain unsolved. WTF! Walk up to the Pi. Unplug it. Take it to a usable HDMI display. Plug it in. Fix any (possible but unlikely) issues caused by powering it down hard. Reconfigure the display subsystem for the new monitor. Fix the network issue. Take it back to where it goes. Plug it back in. -Dave On 08/22/2017 09:37 AM, William Dudley via vcf-midatlantic wrote:
If one needs to fiddle a config file to get composite video out, then that would be a show stopper for fixing the pi.
I await test results.
Bill
This email is free of malware because I run Linux.
On Tue, Aug 22, 2017 at 1:19 AM, Evan Koblentz via vcf-midatlantic < vcf-midatlantic@lists.vintagecomputerfederation.org> wrote:
Hey look!
http://www.robotshop.com/en/raspberry-pi-vga-adapter.html
Ethan Dicks (VCF East frequent PDP-8 exhibitor) turned me on to this.
He teaches Pi classes at his local hackerspace. He said that in his experience the Pi usually "just works" to detect the video type, but that it's more reliable when you edit the config file.
For 7 bucks I am definitely buying us one.
I already have a low-profile widescreen VGA LCD at home that's the perfect size for our application. (VCF's existing supply of VGA LCDs are all square-shaped.)
All's well that ends well.
-- Dave McGuire, AK4HZ New Kensington, PA
OH MY GOD. I CANNOT TAKE THIS ANYMORE. After 25 messages and three days, two problems that any reasonable person would have solved in about five minutes remain unsolved.
Nobody ever accused me of being reasonable. :)
Walk up to the Pi. Unplug it. Take it to a usable HDMI display. Plug it in. Fix any (possible but unlikely) issues caused by powering it down hard. Reconfigure the display subsystem for the new monitor. Fix the network issue. Take it back to where it goes. Plug it back in.
In our defense, we were trying to fix things possibly related to our local network, but we didn't have a conveniently accessible HDMI monitor there. Ergo the chicken and egg. However I did not know about editing the file by moving the microSD card to another computer entirely, as Jeff Galinant suggested.
Dave, The pi was powered down without an orderly shutdown a couple of months ago. It took me HOURS to fix the corrupted files on the SD card. If you would like to take responsibility for this project, feel free to step up. Otherwise, just silently hit the delete key on emails in this thread. Bill Dudley This email is free of malware because I run Linux. On Tue, Aug 22, 2017 at 2:19 PM, Evan Koblentz via vcf-midatlantic < vcf-midatlantic@lists.vintagecomputerfederation.org> wrote:
OH MY GOD. I CANNOT TAKE THIS ANYMORE. After 25 messages and three
days, two problems that any reasonable person would have solved in about five minutes remain unsolved.
Nobody ever accused me of being reasonable. :)
Walk up to the Pi. Unplug it. Take it to a usable HDMI display.
Plug it in. Fix any (possible but unlikely) issues caused by powering it down hard. Reconfigure the display subsystem for the new monitor. Fix the network issue. Take it back to where it goes. Plug it back in.
In our defense, we were trying to fix things possibly related to our local network, but we didn't have a conveniently accessible HDMI monitor there. Ergo the chicken and egg.
However I did not know about editing the file by moving the microSD card to another computer entirely, as Jeff Galinant suggested.
On 08/22/2017 04:36 PM, William Dudley via vcf-midatlantic wrote:
The pi was powered down without an orderly shutdown a couple of months ago. It took me HOURS to fix the corrupted files on the SD card.
You and Evan have spent HOURS agonizing over how to approach this project as it is, and gotten nowhere. Further, about that previous incident, in the name of God WHY did it take HOURS to rewrite a bootable Linux image on an SD card and restore your files? That, too, is a five-minute fix! And even further, I believe Evan said the machine had dropped off of the network. In this situation, you must assume that the contents of the SD card are already corrupt, so plan on doing that five minutes of work anyway.
If you would like to take responsibility for this project, feel free to step up.
Oh good heavens, believe me I would, were it not for the fact that I'm five hours away. Anything would be better than watching this debacle.
Otherwise, just silently hit the delete key on emails in this thread.
I'm sorry Bill, but I feel compelled to help people whose welfare I care about stop hitting themselves in the head with hammers. I've told you and Evan what you need to do. It's up to you to either do it, or keep hitting yourselves in the head with hammers. -Dave -- Dave McGuire, AK4HZ New Kensington, PA
On Aug 22, 2017, at 4:36 PM, William Dudley via vcf-midatlantic <vcf-midatlantic@lists.vintagecomputerfederation.org> wrote:
Dave,
The pi was powered down without an orderly shutdown a couple of months ago.
It took me HOURS to fix the corrupted files on the SD card.
If you would like to take responsibility for this project, feel free to step up.
Otherwise, just silently hit the delete key on emails in this thread.
Bill Dudley
This email is free of malware because I run Linux.
On Tue, Aug 22, 2017 at 2:19 PM, Evan Koblentz via vcf-midatlantic < vcf-midatlantic@lists.vintagecomputerfederation.org> wrote:
OH MY GOD. I CANNOT TAKE THIS ANYMORE. After 25 messages and three
days, two problems that any reasonable person would have solved in about five minutes remain unsolved.
Nobody ever accused me of being reasonable. :)
Walk up to the Pi. Unplug it. Take it to a usable HDMI display.
Plug it in. Fix any (possible but unlikely) issues caused by powering it down hard. Reconfigure the display subsystem for the new monitor. Fix the network issue. Take it back to where it goes. Plug it back in.
In our defense, we were trying to fix things possibly related to our local network, but we didn't have a conveniently accessible HDMI monitor there. Ergo the chicken and egg.
However I did not know about editing the file by moving the microSD card to another computer entirely, as Jeff Galinant suggested.
FYI. I have found that if you powerdown the PI from the AC side of the power adapter it has a good chance of corrupting boot drive. But if you put the switch on the D.C. side and use that instead, I have yet to corrupt an image. Also I don't know why the museum doesn't keep a copy of the disk image on the desktop computer so that if the PI doesn't boot, they can simply re-image the sdcard in 5 minutes and we can avoid this thread being rehashed in 6 months.
On Tue, Aug 22, 2017 at 7:36 PM, corey cohen via vcf-midatlantic < vcf-midatlantic@lists.vintagecomputerfederation.org> wrote:
FYI. I have found that if you powerdown the PI from the AC side of the power adapter it has a good chance of corrupting boot drive. But if you put the switch on the D.C. side and use that instead, I have yet to corrupt an image.
i seriously doubt there is some magical combination of power off sequences to resolve this, some people on the RPi forums claim this to be the different SD types, class 10 vs class 4, etc But nobody has gotten the same class to work reliably, because you can't when you deliberately shutoff the power even though this is an embedded linux computer, eg, instant on, "instant off" -- it's not >exactly< instant off btw, as you may have noticed, it's not exactly "instant on" either in simple terms, because there's still a file system which spools the writes to the SD card in a background process., so you're corrupting the disk before the write operations are completed by unplugging the power. On your linux desktop do you actually unplug the power cord, No, you click on the shutdown button to safely power off, cause you will get the same result, a corrupted hard disk what your supposed to have in lieu of a keyboard/mouse is a Shutdown button wired to the gpio expansion header, this allows you to safely shutoff the Pi, simple as that, without corruption to the sd card there's 100s of examples, like this one, http://www.instructables.com/id/Simple-Raspberry-Pi-Shutdown-Button/ now there's more exotic options out there that others may chime in about, but to get you going, this is the most simplest option to start with. a tiny push button switch, resistor, pairs of wires, and a script to run in the background process - you're done
Also I don't know why the museum doesn't keep a copy of the disk image on the desktop computer so that if the PI doesn't boot, they can simply re-image the sdcard in 5 minutes and we can avoid this thread being rehashed in 6 months.
exactly with the shutdown button, corruption will be minimized but you still have storms where you lose power this is where you like to have battery backup and if you spend the extra effort, you can have the system detect the battery backup was activated and email your IT/RPi guy to warn him the battery will give still you hours and hours of use, but you still want to go in and reset the battery backup eventually Dan _ ____ / \__/ Scotty, We Need More Power !! \_/ _\__ Aye, Cap'n, but we've only got 80 columns !!
I'll make an EE guess here: When you unplug the DC side, the Pi is shut off relatively quickly so there is little room for bad writes to corrupt the card, or for the voltage to drop low enough for the CPU to execute random instructions but still high enough to run at all. When you unplug the AC side of the power adapter, the capacitance in the power supply causes a much slower drop-off which causes the CPU to execute random instructions, likely writing to the card. So far I haven't yet corrupted a card, but I generally power Pis from USB and unplug the USB cable first. My suggestions? Make the Linux setup as read-only as possible as that will minimize possibility of corruption, and of course, if the image contents are static, keep a copy of the image handy on a nearby PC. Constant writing will quickly kill the SD card anyway. David
On Aug 22, 2017, at 8:16 PM, Dan Roganti via vcf-midatlantic <vcf-midatlantic@lists.vintagecomputerfederation.org> wrote:
On Tue, Aug 22, 2017 at 7:36 PM, corey cohen via vcf-midatlantic < vcf-midatlantic@lists.vintagecomputerfederation.org> wrote:
FYI. I have found that if you powerdown the PI from the AC side of the power adapter it has a good chance of corrupting boot drive. But if you put the switch on the D.C. side and use that instead, I have yet to corrupt an image.
i seriously doubt there is some magical combination of power off sequences to resolve this, some people on the RPi forums claim this to be the different SD types, class 10 vs class 4, etc But nobody has gotten the same class to work reliably, because you can't when you deliberately shutoff the power
even though this is an embedded linux computer, eg, instant on, "instant off" -- it's not >exactly< instant off btw, as you may have noticed, it's not exactly "instant on" either in simple terms, because there's still a file system which spools the writes to the SD card in a background process., so you're corrupting the disk before the write operations are completed by unplugging the power.
On your linux desktop do you actually unplug the power cord, No, you click on the shutdown button to safely power off, cause you will get the same result, a corrupted hard disk
what your supposed to have in lieu of a keyboard/mouse is a Shutdown button wired to the gpio expansion header, this allows you to safely shutoff the Pi, simple as that, without corruption to the sd card there's 100s of examples, like this one, http://www.instructables.com/id/Simple-Raspberry-Pi-Shutdown-Button/
now there's more exotic options out there that others may chime in about, but to get you going, this is the most simplest option to start with. a tiny push button switch, resistor, pairs of wires, and a script to run in the background process - you're done
Also I don't know why the museum doesn't keep a copy of the disk image on the desktop computer so that if the PI doesn't boot, they can simply re-image the sdcard in 5 minutes and we can avoid this thread being rehashed in 6 months.
exactly with the shutdown button, corruption will be minimized but you still have storms where you lose power this is where you like to have battery backup and if you spend the extra effort, you can have the system detect the battery backup was activated and email your IT/RPi guy to warn him the battery will give still you hours and hours of use, but you still want to go in and reset the battery backup eventually Dan
_ ____ / \__/ Scotty, We Need More Power !! \_/ _\__ Aye, Cap'n, but we've only got 80 columns !!
Guys, all I did was ask for a monitor. All the second-guessing is overkill. Bill Dudley knows his stuff. Someone (not me) accidentally turned off the power one time. Learned our lesson; now we'll keep a backup. Can we move on please...
On 08/22/2017 08:21 PM, David Ryskalczyk via vcf-midatlantic wrote:
I'll make an EE guess here: When you unplug the DC side, the Pi is shut off relatively quickly so there is little room for bad writes to corrupt the card, or for the voltage to drop low enough for the CPU to execute random instructions but still high enough to run at all. When you unplug the AC side of the power adapter, the capacitance in the power supply causes a much slower drop-off which causes the CPU to execute random instructions, likely writing to the card.
I think the USB PS tend to be more inductive than capacitive.
My suggestions? Make the Linux setup as read-only as possible as that will minimize possibility of corruption, and of course, if the image contents are static, keep a copy of the image handy on a nearby PC. Constant writing will quickly kill the SD card anyway.
This will help, you can setup a share using either NFS or Samba (CIFS). You can then write to that. But there are some things that need to write to files. The OS part of Linux generally doesn't need this but the applications (rsyslog, email, etc) does and they also tend to try and write out logs. That's a distribution issue. Pulling power from the DC end (that part that plugs into the Pi directly) is probably not a bad idea. But not until you've run the shutdown cmd. So to properly shutdown the Pi, run the shutdown command or use Dave's suggestion of the pushbutton solution. I like that one but protect the button and don't make it a big red button that say don't push. People will want to push it. I'm sure there are more than a few of us with stories of idiots pushing the emergency power off on mainframes. -- Linux Home Automation Neil Cherry ncherry@linuxha.com http://www.linuxha.com/ Main site http://linuxha.blogspot.com/ My HA Blog Author of: Linux Smart Homes For Dummies
We are currently trying to install the shutdown button and associated script, but couldn't install the script as we lost the ability to ssh into the pi. So we can't power it down properly, we can't edit config files, and we can't fix ssh without the monitor. Bill Dudley On Aug 23, 2017 8:30 AM, "Neil Cherry via vcf-midatlantic" < vcf-midatlantic@lists.vintagecomputerfederation.org> wrote:
On 08/22/2017 08:21 PM, David Ryskalczyk via vcf-midatlantic wrote:
I'll make an EE guess here: When you unplug the DC side, the Pi is shut off relatively quickly so there is little room for bad writes to corrupt the card, or for the voltage to drop low enough for the CPU to execute random instructions but still high enough to run at all. When you unplug the AC side of the power adapter, the capacitance in the power supply causes a much slower drop-off which causes the CPU to execute random instructions, likely writing to the card.
I think the USB PS tend to be more inductive than capacitive.
My suggestions? Make the Linux setup as read-only as possible as that will
minimize possibility of corruption, and of course, if the image contents are static, keep a copy of the image handy on a nearby PC. Constant writing will quickly kill the SD card anyway.
This will help, you can setup a share using either NFS or Samba (CIFS). You can then write to that.
But there are some things that need to write to files. The OS part of Linux generally doesn't need this but the applications (rsyslog, email, etc) does and they also tend to try and write out logs. That's a distribution issue.
Pulling power from the DC end (that part that plugs into the Pi directly) is probably not a bad idea. But not until you've run the shutdown cmd. So to properly shutdown the Pi, run the shutdown command or use Dave's suggestion of the pushbutton solution. I like that one but protect the button and don't make it a big red button that say don't push. People will want to push it.
I'm sure there are more than a few of us with stories of idiots pushing the emergency power off on mainframes.
-- Linux Home Automation Neil Cherry ncherry@linuxha.com http://www.linuxha.com/ Main site http://linuxha.blogspot.com/ My HA Blog Author of: Linux Smart Homes For Dummies
Could I ask a question? How often does this happen? Ok, two questions... what happens when the power goes off? (No talk about how reliable the power is at IA.) Just pull the f%^&ing plug and reboot the Pi. It has a journaling file system and will check the file system if needed. Why all the fuss? Occasionally it might be a good idea to make a copy of the uSD card as a backup. Jim On Wed, 23 Aug 2017, William Dudley via vcf-midatlantic wrote:
Date: Wed, 23 Aug 2017 09:31:40 -0400 From: William Dudley via vcf-midatlantic <vcf-midatlantic@lists.vintagecomputerfederation.org> To: vcf-midatlantic <vcf-midatlantic@lists.vintagecomputerfederation.org> Cc: William Dudley <wfdudley@gmail.com> Subject: Re: [vcf-midatlantic] Monitor needed for museum
We are currently trying to install the shutdown button and associated script, but couldn't install the script as we lost the ability to ssh into the pi. So we can't power it down properly, we can't edit config files, and we can't fix ssh without the monitor.
Bill Dudley
On Aug 23, 2017 8:30 AM, "Neil Cherry via vcf-midatlantic" < vcf-midatlantic@lists.vintagecomputerfederation.org> wrote:
On 08/22/2017 08:21 PM, David Ryskalczyk via vcf-midatlantic wrote:
I'll make an EE guess here: When you unplug the DC side, the Pi is shut off relatively quickly so there is little room for bad writes to corrupt the card, or for the voltage to drop low enough for the CPU to execute random instructions but still high enough to run at all. When you unplug the AC side of the power adapter, the capacitance in the power supply causes a much slower drop-off which causes the CPU to execute random instructions, likely writing to the card.
I think the USB PS tend to be more inductive than capacitive.
My suggestions? Make the Linux setup as read-only as possible as that will
minimize possibility of corruption, and of course, if the image contents are static, keep a copy of the image handy on a nearby PC. Constant writing will quickly kill the SD card anyway.
This will help, you can setup a share using either NFS or Samba (CIFS). You can then write to that.
But there are some things that need to write to files. The OS part of Linux generally doesn't need this but the applications (rsyslog, email, etc) does and they also tend to try and write out logs. That's a distribution issue.
Pulling power from the DC end (that part that plugs into the Pi directly) is probably not a bad idea. But not until you've run the shutdown cmd. So to properly shutdown the Pi, run the shutdown command or use Dave's suggestion of the pushbutton solution. I like that one but protect the button and don't make it a big red button that say don't push. People will want to push it.
I'm sure there are more than a few of us with stories of idiots pushing the emergency power off on mainframes.
-- Linux Home Automation Neil Cherry ncherry@linuxha.com http://www.linuxha.com/ Main site http://linuxha.blogspot.com/ My HA Blog Author of: Linux Smart Homes For Dummies
js@sdf.org SDF Public Access UNIX System - http://sdf.lonestar.org
I do know that PI's are famous for corrupting the boot disk. A couple of work arounds, use a cheap phone booster as a UPS, http://raspi-ups.appspot.com/en/index.jsp or change the PI to boot from USB stick. An old article on this is here:- https://samhobbs.co.uk/2013/10/speed-up-your-pi-by-booting-to-a-usb-flash-dr ive Dave
-----Original Message----- From: vcf-midatlantic [mailto:vcf-midatlantic- bounces@lists.vintagecomputerfederation.org] On Behalf Of Jim Scheef via vcf-midatlantic Sent: 26 August 2017 14:50 To: William Dudley via vcf-midatlantic <vcf- midatlantic@lists.vintagecomputerfederation.org> Cc: Jim Scheef <js@sdf.org> Subject: Re: [vcf-midatlantic] Monitor needed for museum
Could I ask a question? How often does this happen? Ok, two questions... what happens when the power goes off? (No talk about how reliable the power is at IA.) Just pull the f%^&ing plug and reboot the Pi. It has a journaling file system and will check the file system if needed. Why all the fuss? Occasionally it might be a good idea to make a copy of the uSD card as a backup. Jim
On Wed, 23 Aug 2017, William Dudley via vcf-midatlantic wrote:
Date: Wed, 23 Aug 2017 09:31:40 -0400 From: William Dudley via vcf-midatlantic <vcf-midatlantic@lists.vintagecomputerfederation.org> To: vcf-midatlantic <vcf-midatlantic@lists.vintagecomputerfederation.org> Cc: William Dudley <wfdudley@gmail.com> Subject: Re: [vcf-midatlantic] Monitor needed for museum
We are currently trying to install the shutdown button and associated script, but couldn't install the script as we lost the ability to ssh into the pi. So we can't power it down properly, we can't edit config files, and we can't fix ssh without the monitor.
Bill Dudley
On Aug 23, 2017 8:30 AM, "Neil Cherry via vcf-midatlantic" < vcf-midatlantic@lists.vintagecomputerfederation.org> wrote:
On 08/22/2017 08:21 PM, David Ryskalczyk via vcf-midatlantic wrote:
I'll make an EE guess here: When you unplug the DC side, the Pi is shut off relatively quickly so there is little room for bad writes to corrupt the card, or for the voltage to drop low enough for the CPU to execute random instructions but still high enough to run at all. When you unplug the AC side of the power adapter, the capacitance in the power supply causes a much slower drop-off which causes the CPU to execute random instructions, likely writing to the card.
I think the USB PS tend to be more inductive than capacitive.
My suggestions? Make the Linux setup as read-only as possible as that will
minimize possibility of corruption, and of course, if the image contents are static, keep a copy of the image handy on a nearby PC. Constant writing will quickly kill the SD card anyway.
This will help, you can setup a share using either NFS or Samba (CIFS). You can then write to that.
But there are some things that need to write to files. The OS part of Linux generally doesn't need this but the applications (rsyslog, email, etc) does and they also tend to try and write out logs. That's a distribution issue.
Pulling power from the DC end (that part that plugs into the Pi directly) is probably not a bad idea. But not until you've run the shutdown cmd. So to properly shutdown the Pi, run the shutdown command or use Dave's suggestion of the pushbutton solution. I like that one but protect the button and don't make it a big red button that say don't push. People will want to push it.
I'm sure there are more than a few of us with stories of idiots pushing the emergency power off on mainframes.
-- Linux Home Automation Neil Cherry ncherry@linuxha.com http://www.linuxha.com/ Main site http://linuxha.blogspot.com/ My HA Blog Author of: Linux Smart Homes For Dummies
js@sdf.org SDF Public Access UNIX System - http://sdf.lonestar.org
Power banks are notorious for leaking power, and ones that can be left in-line (simultaneous charges and power) are expensive. On Sat, Aug 26, 2017 at 2:36 PM Dave Wade via vcf-midatlantic < vcf-midatlantic@lists.vintagecomputerfederation.org> wrote:
I do know that PI's are famous for corrupting the boot disk. A couple of work arounds, use a cheap phone booster as a UPS,
http://raspi-ups.appspot.com/en/index.jsp
or change the PI to boot from USB stick.
An old article on this is here:-
https://samhobbs.co.uk/2013/10/speed-up-your-pi-by-booting-to-a-usb-flash-dr ive
Dave
-----Original Message----- From: vcf-midatlantic [mailto:vcf-midatlantic- bounces@lists.vintagecomputerfederation.org] On Behalf Of Jim Scheef via vcf-midatlantic Sent: 26 August 2017 14:50 To: William Dudley via vcf-midatlantic <vcf- midatlantic@lists.vintagecomputerfederation.org> Cc: Jim Scheef <js@sdf.org> Subject: Re: [vcf-midatlantic] Monitor needed for museum
Could I ask a question? How often does this happen? Ok, two questions... what happens when the power goes off? (No talk about how reliable the power is at IA.) Just pull the f%^&ing plug and reboot the Pi. It has a journaling file system and will check the file system if needed. Why all the fuss? Occasionally it might be a good idea to make a copy of the uSD card as a backup. Jim
On Wed, 23 Aug 2017, William Dudley via vcf-midatlantic wrote:
Date: Wed, 23 Aug 2017 09:31:40 -0400 From: William Dudley via vcf-midatlantic <vcf-midatlantic@lists.vintagecomputerfederation.org> To: vcf-midatlantic <vcf-midatlantic@lists.vintagecomputerfederation.org> Cc: William Dudley <wfdudley@gmail.com> Subject: Re: [vcf-midatlantic] Monitor needed for museum
We are currently trying to install the shutdown button and associated script, but couldn't install the script as we lost the ability to ssh into the pi. So we can't power it down properly, we can't edit config files, and we can't fix ssh without the monitor.
Bill Dudley
On Aug 23, 2017 8:30 AM, "Neil Cherry via vcf-midatlantic" < vcf-midatlantic@lists.vintagecomputerfederation.org> wrote:
On 08/22/2017 08:21 PM, David Ryskalczyk via vcf-midatlantic wrote:
I'll make an EE guess here: When you unplug the DC side, the Pi is shut off relatively quickly so there is little room for bad writes to corrupt the card, or for the voltage to drop low enough for the CPU to execute random instructions but still high enough to run at all. When you unplug the AC side of the power adapter, the capacitance in the power supply causes a much slower drop-off which causes the CPU to execute random instructions, likely writing to the card.
I think the USB PS tend to be more inductive than capacitive.
My suggestions? Make the Linux setup as read-only as possible as that will
minimize possibility of corruption, and of course, if the image contents are static, keep a copy of the image handy on a nearby PC. Constant writing will quickly kill the SD card anyway.
This will help, you can setup a share using either NFS or Samba (CIFS). You can then write to that.
But there are some things that need to write to files. The OS part of Linux generally doesn't need this but the applications (rsyslog, email, etc) does and they also tend to try and write out logs. That's a distribution issue.
Pulling power from the DC end (that part that plugs into the Pi directly) is probably not a bad idea. But not until you've run the shutdown cmd. So to properly shutdown the Pi, run the shutdown command or use Dave's suggestion of the pushbutton solution. I like that one but protect the button and don't make it a big red button that say don't push. People will want to push it.
I'm sure there are more than a few of us with stories of idiots pushing the emergency power off on mainframes.
-- Linux Home Automation Neil Cherry ncherry@linuxha.com http://www.linuxha.com/ Main site http://linuxha.blogspot.com/ My HA Blog Author of: Linux Smart Homes For Dummies
js@sdf.org SDF Public Access UNIX System - http://sdf.lonestar.org
I don't know why the museum doesn't keep a copy of the disk image on the desktop computer so that if the PI doesn't boot, they can simply re-image the sdcard in 5 minutes and we can avoid this thread being rehashed in 6 months.
We will now.
On Tue, Aug 22, 2017 at 2:19 PM, Evan Koblentz via vcf-midatlantic < vcf-midatlantic@lists.vintagecomputerfederation.org> wrote:
Nobody ever accused me of being reasonable. :)
we know it comes from your magnetic personality ;)
In our defense, we were trying to fix things possibly related to our local network, but we didn't have a conveniently accessible HDMI monitor there. Ergo the chicken and egg.
here again, I think you need to be aware that modern VGA LCD monitors from the last 5yrs are already capable of 1920x1080 ie, hdmi resolution which is what I said at midnight -- a lot easier to find and borrow -- and I bet you $20 that IXR has one or they know where there is one. so your hdmi to vga would have worked perfectly then, and then to fix the remote login problem, and never have a need for a hdmi monitor
However I did not know about editing the file by moving the microSD card to another computer entirely, as Jeff Galinant suggested.
those links I sent at midnight after no one bothered to reply to you after 6hrs explained all of this. I'm not expecting you to be an Linux expert, I'm not a Linux expert, but i expect you to read -- you've done that before to solve other problems. And that file can be edited right on the RPi , no need for any other machine. So you could have adjusted the video mode right there to support the 10yrs monitor - which is most likely - without a doubt stops at 800x600 By using the existing hi-res vga Lcd monitor, because that supports practically every video mode from here to eternity.
From what you said the RPi was still running, you just had the wrong monitor Dan
-- _ ____ / \__/ Scotty, We Need More Power !! \_/ _\__ Aye, Cap'n, but we've only got 80 columns !!
participants (11)
-
corey cohen -
Dan Roganti -
Dave McGuire -
Dave Wade -
David Ryskalczyk -
Dean Notarnicola -
Evan Koblentz -
Jeff Galinat -
Jim Scheef -
Neil Cherry -
William Dudley