Friday, January 22, 2010

Networked memory

I just read an interesting article about how slime mold generates networks as efficient as the Tokyo Subway system, the only downfall looks to be related to redundancy.
Slime Mold Subways

Which get's me thinking, now that memory is a dime a dozen, can we have networks of the same data, and depending on where you are in the platter for example rather then having to travel say all the way across the platter to get the information, you can just stay in the local vicinity?

So Suppose you have the same data being transferred back and forth in different memory regions so they are all matching. Your head is already in a particular location of the platter, now rather then having to say move the head all the way from where it is to a location nearly opposite the location you currently are, there is a networked memory piece just a few micrometer's next to, or after what you're looking at. Now the disk doesn't need to seek as long, which tends to be the more time consuming part of data access.

Let me know what you think or do you think I'm off my rocker?

Monday, January 11, 2010

Deleting Files

I was having problems with a particular file, one of my scripts accidentally produced a file named such that I couldn't delete it.
I found a great tip here: Forum Post

All I had to do was find the filename using dir /x /a

Once i found that a simple del filename got rid of it.

Saturday, January 9, 2010

Analog Inputs

I've been fighting since late last night trying to get analog inputs working on my PIC16F684.

I finally got somewhere this evening, oddly enough for some reason, in some regions of the pot it goes really quick then just a small bit over will slow it down drastically.

All my code does is initialize everything to setup RA0 as an analog input, then it turns on the ADC waits until it's done then toggles the LED and waits the amount of time in the combination of ADRESH and ADRESL, all I had to do was put ADRESH into the integer value I had, shift it 8 positions left, then or the ADRESL in, then pass it to my wait routine.

Outside of that it's finally working, the last hiccup I had was well frankly I forgot to turn it back on after trying turning it off as a troubleshooting measure. Of Course I'll continue to plug VERSION CONTROL, had I gotten this working and decided to play a little here and there to make it say be more sensitive, I may have done myself in by messing something up, now I have no fear of that.

I am posting the code on my SVN server, and one day would like to be able to make that public so everyone can get to it, but I suspect my ISP won't like me using a web server out of my house, so I'll for now plan to upload it to Google Docs.

Below you'll find the vid of the PIC Kit 1 in action with the LED's toggling quickly then as I rotate the pot it slows down.

video

Here's the code to do it, there may be some unneeded stuff, let me know if you see anything off!

For the sake of testing I uploaded this file to YouTube and am going to see what the difference in appearance is here!


Thursday, January 7, 2010

Opening Mailto in Gmail in XP

One of the first things I did when I bought my netbook was to download chrome. Now I haven't actually clicked a mailto link until today, and guess what happened? Internet explorer in all it's glory opened up. I didn't like that. One of the solutions I found was to look for URI.mailto or something to that effect in the file types menu of an explorer window and make some changes there, but well I didn't like that method much and I couldn't find what they were talking about in the first place.

I started searching for the term mailto in the registry, and I came upon this line right below.

HKEY_CLASSES_ROOT\mailto\shell\open\command

Unfortunately I deleted the original line so if anyone has it I would really like to know what it originally said, but none the less I have the line to insert if you want Chrome to open up gmail and insert the mail address!

This brings me to my next point ALWAYS BACKUP YOUR REGISTRY in case you muck something up.

I changed the key
to the below (change out onaclov for your username) and you should be set to go! Of course if you want to use another type of email client and/or browser you're going to have to change a few things. Basically all I'm doing is calling the chrome application, and passing the gmail address with mailto and URL %1 passed to it. The ideal way would be to call the default browser

"C:\Documents and Settings\onaclov\Local Settings\Application Data\Google\Chrome\Application\chrome.exe" --app=https://mail.google.com/mail?extsrc=mailto&url=%1

Additional Notes:
Oddly enough I found that if I go to IE and click options and then programs it only shows Outlook Express and Windows Live Mail which I initially thought was the culprit and in some ways it might have been, so I did a search for Windows Live Mail.

I found this:
As you can see it looks like mine has an entry for GMAIL, which of course is completely incorrect
as I was testing some things out trying to get it to work, if you add a Key there and name it whatever you name it, when you go to IE and Tool Options and Programs and Email you'll see those entries the problem is I have/had no idea what to put in there which lead me to the initial piece of the post finding mailto.

If I had the original mailto contents I "might" be able to remember what that was doing and possibly setup the entry on the left (HKEY_LOCAL_MACHINE\SOFTWARE\Clients\Mail\Gmail) to actually open whatever browser you want as well as whatever email client you want based on that location (rather then having to keep entering in the registry if you decide to change).

Well if you have any other items of note please let me know.

Good luck

Wednesday, January 6, 2010

Interrupts

In ECE 344 we learned about interrupts and how to use them, of course we were programming in assembly, so we had to setup our interrupt vector, then write some code at the appropriate offset.

That turned out to be pretty easy, but the problem is let's say we want to write some code in C and try to handle interrupts. This is a little tricky if you don't have all the information you need.

Well of course since I can't seem to think logically sometimes, I didn't look at any manuals and just headed over to stackoverflow.com, where I got some great answer's here: Interrupts

The simple answer was this:
void interrupt my_interrupt_handler (void) {
handle_interrupts_here();
}
I did some testing and once I had the right bit's turned on I just ended up in my interrupt routine with this (about 90% borrowed from here:Microchipc):
void interrupt isr(void)
{
if (T0IF)
{
TMR0=TMR0_SETTING;
T0IF=0;
RA5=1;
//code right here is executed every 800us
}

My newest project I'll be working on with this microcontroller is to find some way to create a simple serial interface which I can transmit and receive a piece of data. Since I can interrupt on a timed interval. I should be able to read data passed at an expected rate.

I'll keep you updated when I get more work done.

Sunday, January 3, 2010

SVN

So today I would like to go over the importance of version control.

Take for example I was working on a program, I made some changes and it was working. Now rather then checking in my file and version controlling it, I just started modifying it. About half ways through I realized I meant to re-save the file somewhere but instead overwrote the changes that I had originally working.

When you've gotten a particular program working at some point, if you're dedicated enough to stick to version control, you check it in, then keep working, now if you have made changes and wish to revert to a previous working state it's REALLY EASY. Now of course simple enough you can just save multiple copies of a file, and keep renaming it and everything else. If you use version control you really only "see" one file and you just keep checking it in.

I have SVN setup on my server, and am using Tortoise SVN for my window's machine, and am enthralled with it. When you do a checkout in SVN it ends up copying the checked out folder into your current directory. Now when you make changes it shows a different icon on the folders so you can visually see that it's needing to be committed. Now if you're working with multiple machines/people you will want to make sure you update before commiting.

Once you've committed changes you're set.

Good luck and let me know if you need any help setting up your very own SVN server.

Max RPM II

Well I finally got a few minutes to mess with my arcade after cleaning the garage a bit.

So far I have the lights on the coin op working, the flourescent light doesn't fully light, so I need to find out if it's the wattage or what. The monitor doesn't turn on at all, and the speakers just give a hum. I have to assume that the system isn't "booting". I found a site I can use to help me with questions here: Arcade Museum

I have 120V going to my monitor and have checked a few IC's on the Turbo Cheap Squeak.

In the hopes of using another computer monitor I tried hooking up the Horizontal sync to a regular CRT, and the monitor said the frequency wasn't correct. So at this point I'm assuming that it's a no go on that CRT.

I'll post updates as they come along. Have fun!