Re: Wrench icon gone?
Posted: Fri May 23, 2025 7:00 pm
I'll keep an eye open for that.
I think that the Zumos show the symptoms of a 'memory leak'. When programmers write programs - in order to carry out a particular task, they need a chunk of memory to be able to do it. (Sorting a list is a good example - you need a chunk of memory to provide space to shuffle things around). Once the list is sorted, that chunk of memory can be used for something else.
So before the (eg) sort can take place the programmer has to 'allocate' say 1 Gb of memory to the task - so no other operation going on in the computer can use it. When the task has finished, the programmer has to 'de-allocate' it so that other routines can use it if they want.
That is all very straight forward. Its the computing equivalent of going into a toilet cubicle and locking the door. Nothing can use that cubicle until the 'visitor' had left and the door is unlocked.
Except while the Zumo is doing that, the user is doing all sorts of things, which may interrupt the sort process. So unless the programmer is aware of every single interruption that can take place the 'sort' program may never reach the end of what it was doing. So it never gets to deallocate the chunk of memory. A good programmer will be able to cater for this. But if something happens that s/he hasn't catered for - like the toilet door handle dropping off - then the visitor ends his occupancy in some other way - like crawling under the door. The visitor has finished, but the cubicle is still not available for anyone else. There are now fewer number of cubicles - or for the computer, much less memory - than there was before. Some of the capacity has leaked away. (Sorry, not an image I intended to portray !)
For the computer the only way to recover this is to re-boot it, stop all running programs and let the system software put everything back as it should be.
When you unplugged the USB cable, that is exactly what the XT does. Which is why when you call technical support, the first thing that they will ask you to do is power it off (fully) and let it reboot. It unlocks all of the available memory so that things can work properly.
I'm not suggesting that this is exactly what is happening, but that sort of thing happens a lot. Just today I was using some graphic software - and had been using it for a while, and it started leaving ghost images when I moved objects about. So I thought - it is running out of memory and about to crash - so I saved everything, closed the program and then reloaded it and opened up what I had been working on. Then performed the same operation and it worked fine.
I think that the Zumos show the symptoms of a 'memory leak'. When programmers write programs - in order to carry out a particular task, they need a chunk of memory to be able to do it. (Sorting a list is a good example - you need a chunk of memory to provide space to shuffle things around). Once the list is sorted, that chunk of memory can be used for something else.
So before the (eg) sort can take place the programmer has to 'allocate' say 1 Gb of memory to the task - so no other operation going on in the computer can use it. When the task has finished, the programmer has to 'de-allocate' it so that other routines can use it if they want.
That is all very straight forward. Its the computing equivalent of going into a toilet cubicle and locking the door. Nothing can use that cubicle until the 'visitor' had left and the door is unlocked.
Except while the Zumo is doing that, the user is doing all sorts of things, which may interrupt the sort process. So unless the programmer is aware of every single interruption that can take place the 'sort' program may never reach the end of what it was doing. So it never gets to deallocate the chunk of memory. A good programmer will be able to cater for this. But if something happens that s/he hasn't catered for - like the toilet door handle dropping off - then the visitor ends his occupancy in some other way - like crawling under the door. The visitor has finished, but the cubicle is still not available for anyone else. There are now fewer number of cubicles - or for the computer, much less memory - than there was before. Some of the capacity has leaked away. (Sorry, not an image I intended to portray !)
For the computer the only way to recover this is to re-boot it, stop all running programs and let the system software put everything back as it should be.
When you unplugged the USB cable, that is exactly what the XT does. Which is why when you call technical support, the first thing that they will ask you to do is power it off (fully) and let it reboot. It unlocks all of the available memory so that things can work properly.
I'm not suggesting that this is exactly what is happening, but that sort of thing happens a lot. Just today I was using some graphic software - and had been using it for a while, and it started leaving ghost images when I moved objects about. So I thought - it is running out of memory and about to crash - so I saved everything, closed the program and then reloaded it and opened up what I had been working on. Then performed the same operation and it worked fine.