I'm currently reading a computer organization book and i'm so confused about Input/Output mechanism and have lots of questions in my mind.
As i understood there are two concepts for communicating with peripherals, first one is Memory Mapped I/O and the other one is I/O(Port) Mapped I/O.If the architecture is based on Memory Mapped I/O there are no special I/O instructions like "in","out" etc and device registers are mapped to memory address space so we can read or write to peripheral ports by "mov" instruction.On the other hand if architecture is based on I/O Mapped I/O, device registers are mapped to I/O address space which is completely separated from memory address space and cpu uses special instructions("in","out","ins","outs" ) for reading or writing to I/O Mapped device registers.
So here is my questions;
1.)If X86 architecture uses I/O(Port,Isolated etc) Mapped I/O technique why there are memory address spaces for devices like graphic card?
2.)If graphic card maps 1 gb memory to main memory address space what does it mean?Does it mean Memory Mapped I/O ?
3.)If x86 architecture doesn't use Memory Mapped I/O how a device can maps itself to memory address space?
4.)If x86 architecture can use Memory Mapped I/O ,how can it use and with which instructions?
5.)If I/O mapping is about mapping peripheral registers why graphic card wants so much space for mapping ?
Ok so I've read that there are some instructions that do things that enable/disable interupts,etc
are these the so-called priviledged instructions ??
do you know if there is a list with all those "strange" instructions ?
In my current customer's environment, we have Windows 7 machines on the factory floor that production people use to get their job done. The accounts they use are quite restricted - historical reasons . Anyway, one thing one of these machines needs to do is some low level formatting of compact flash cards. The commands used require accessing very low level operations like DISKPART, etc, so permissions must be elevated for the script to be able to run.
Normally, I would run this script on my laptop by right clicking on it and Running As Administrator, supply the password and off we go. But we cannot give the admin password out, just not a good idea.
Is there any way to install or set up a script with elevated permissions? I've not done anything like this before, but off the cuff, I'm thinking creating a simple service, installed with priv's and having the non-priv'd script send it a request.
Charlie Gilley Stuck in a dysfunctional matrix from which I must escape...
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I've got my Samsung Galaxy S4 set to automatically connect to the various wireless networks I regularly use, and for the most part it works great. But at home I have it set to use the high band network on my WD MyNet N900 router, while my home network is set to use the low band, and it fails to connect with the message, "Obtaining IP Address." I've double and triple checked the settings on both the phone and the router, and I can't find any inconsistencies, but I know I've seen this message before on some other device. Unfortunately, I can't recall how I fixed it.
But at home I have it set to use the high band network on my WD MyNet N900 router, while my home network is set to use the low band, and it fails to connect with the message, "Obtaining IP Address."
By this do you mean the 5GHz and the 2.4GHz bands?
I find that my Smasung Galaxy S4 won't play nice with the 5GHz band on my router but doesn't miss a beat on the 2.4GHz band.
As for the failing, the only time I have seen this issue on my phone is when attempting to connect to customer WiFi when they have WEP encryption. Not positive, but I think I have had the issue with WPA as well. It woeks all the time with WPA2 though/
"I controlled my laughter and simple said "No,I am very busy,so I can't write any code for you". The moment they heard this all the smiling face turned into a sad looking face and one of them farted. So I had to leave the place as soon as possible." - Mr.Prakash One Fine Saturday. 24/04/2004
I tried the Low band connection with no good results, then spent the evening checking the manuals, tech support and Google for both devices. Nothing. The I went into the phone's settings for the high band connection and selected Show Advanced Options (right under the Show Password option). The resulting screen let me manually configure a static IP address for this connection, and I picked an address within the range of the LAN scope of the router. As soon as I exited the settings screen I had a firm connection. Browsing didn't work right away, as I left the default DNS servers intact the first time around. The phone defaults to the Google free DNS servers at 126.96.36.199 and 188.8.131.52, but neither are very responsive. But after I went back into the setup and changed the DNS servers to my gateway router for #1, and the global server (184.108.40.206) for #2, browsing started working properly.
What makes me crazy about this is that I connect automatically at work to the wireless side of our SonicWall device, and I've never made any special adjustments - it just works. I wonder what makes the WD MyNet N900 act differently? Oh, well, it works...
It was simply a design flaw in the Samsung or the WD router. I think. Automatic configuration just won't work, but setting the connection manually works great. This is only for this router, as far as I can tell, since the phone connects reliably at work or when I'm travelling.
Let it configure automatically and copy and paste the settings here. It could be as simple as a gateway not getting set correctly, which should be a fixable issue.... unless you are perfectly happy with the static connection.
I'm a software engineer with little clue, so please bear with me here.
I have four devices that all have the same, factory-set, IP address, and I need to talk to all of them from the same PC.
The boss said "You should be able to do it with a NAT gateway router with port forwarding", which sounds more like buzzword bingo than any actually useful advice.
I think most cheapo home WiFi routers can do this, but I'm not sure what to look for. It needs to be reasonably cheap, have at least 5 ethernet ports (1 PC, 4 devices), and ideally be configurable so I can assign IP addresses to specific ethernet ports (so regardless of which device is plugged into port 3, it always have the same alias).
That's why I need address translation. If I need to get one router for each, that's fine too.
But I can't configure their IPs, as this is for a factory test setup. Get four devices off the production line, put them in, run the tests. The tests take a few minutes, but are not limited by the PC, so if I can connect four devices and run the tests in parallel, it'll be an enormous time-saver.
You're in deep yogurt, then, because - by definition - no two devices with the same IP address is allowed to exist on one network. If you're planning to ship units that have to have the same IP address, your product will have a very short life cycle. But...
If, for purpose of factory testing, you need to do testing on 4 identical units at once, all with the same address, you have to configure each unit to listen for and respond to test commands on a specific port, and configure the test environment to use fixed addressing with no DHCP service active. You can then spoof the test network into thinking it's hosting one machine with 4 ports, and configure the main router to use port forwarding to talk to each of the machines on its distinct port.
A far better approach would be to either change the IP addresses of the UUTs and run the tests sequentially, or rewrite the tests to run on the UUT as it should be done, and again change the UUT IP address to be unique on the network. The advantage of the latter method is that the test code is downloaded to the UUT and allowed to run, without interaction from the other three machines or the host, until the test is complete. After a decent interval, the test host machine can poll each of the UUTs for test results. If they've blocked you somehow from changing the device IP addresses, tell them to enjoy carnal knowledge of a rolling donut, and go find a job with a real company that has a chance of remaining in business for a while. This one's doomed.
Sorted: One router per device.
The WAN address of the routers statically set to unique addresses, which the PC uses as addresses to the devices.
The LAN address on the routers is set to be the same, i.e. the Default Gateway of the device, and the routers are set to do port forwarding to the device address.
Adds a few hundred bucks to the cost of the test station, which isn't too bad considering the test equipment is tens of thousands.
No need to make any custom settings on any devices, they already come with a static address and a default gateway set up. (The tests aren't run on the UUTs; the test PC is ordering the UUT to transmitt/measure received signals at various power levels andfrequencies.)
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