I’m returning to Awardspace hosting. You can see my blog at http://www.teamtukis.com
I’m returning to Awardspace hosting. You can see my blog at http://www.teamtukis.com
I just moved my site from Awardspace. I’ve been there for probably 5 years. However I only started this blog 8 months ago. It was a painless move. For some strange reason my site is no longer visible on awardspace, and their tech support was little help.
Today is worship of tools day. There are a lot of tools for people to choose from. However the tools I use the most are in the kitchen. Here are a couple list of couple of tools that I consider essential in my kitchen.
My frying pan of choice is the 12inch lodge cast iron skillet. I use this at least 3 times a week. It’s large enough for my family, and cooks very well. It can even be used in the oven. I have several lodge skillets, when cooking smaller amounts I use the 8 inch one instead. If you treat these right, they will last forever.
View skillet at Amazon
There are several recipes for which I require a food slicer. It is difficult to slice food consistently and thinly. I use a chef’s choice meat slicer because it’s inexpensive. I use it for making cottage fries, homemade bacon, shwarma, phillies, and Banh Mi. I have a large family so I need to cut the meat in two sets. This model will overheat after about 2 lbs of frozen meat. Which is sufficient for most families. However we often cook for 10+ people, so I need to let it cool after 2 lbs. I’ve overheated it many times, it includes a thermal cut off switch, which means, I don’t damage when it gets too hot, it simply shuts itself off. I use this slicer several times a month, and have had it for several years, and would recommend it as a good first slicer.
View Slicer at Amazon
Every kitchen needs a mixer, mine is no exception. I have a large kitchen aid mixer. It serves me well, and it is used very often. My only complaints are the motor is a little smaller than I would like, and the gears in the modern ones are now plastic instead of metal. It can handle bread dough up to about 5 cups easily. After that, you have to be careful not to overheat it. Although it does have an overheating sensor to turn it off, it does seem to get damaged when it overheats. If not overheated these will also last a lifetime.
KitchenAid mixer at Amazon
Today is National Frozen Food Day, created in 1984. This is an actual holiday, even Ronald Reagan endorsed it.
The first electric freezer was sold in 1945. It was an american invention. Before this you would use ice and snow to freeze things. However with the electric freezer, you could freeze food quicker. The speed of freezing is important. The faster food is frozen the better quality it will be. Ice crystals get larger the more time it takes to freeze food. This causes cells in the food to burst, which is one of the reasons that freezing berries and then thawing them, allows the liquid to seep out.
Another factor for why food isn’t as good after freezing isn’t because of the freezing process itself. Enzymes are still active even when frozen, they just act at a slower rate. This is particularly noticeable in vegetables. However blanching fresh vegetables well destroy many of the enzymes, allowing them to be frozen with high quality results. This is a great way to store vegetables from your garden. As soon as possible after harvesting, wash and blanch your veggies, then freeze them. Vegetables and fruits lose significant amount of vitamins and nutrients after they are picked. So it is best to freeze them the same day if possible.
However freezing doesn’t kill bacteria, yeast and microbes. They simply become dormant. Parasites can be killed this way. It is recommended to keep food frozen at -4c for 7 days to kill most parasites.
Freezer burn the scourge of frozen food, which is simply food that has dried out. Freezer burned food is safe, just not tasty. According to the USDA freezing at 0 or below keeps food safe indefinitely. However it does deteriorate in flavor and quality, and will eventually not be palitable. Freezer burn can mostly be prevented by wrapping items to be frozen, in airtight packaging. Also make sure the items remain frozen. Thawing and refreezing will also degrade the food.
It is simple to freeze uncooked bread dough, and can save a lot of time. Here’s a recipe for country greek bread.
1/2 cup sourdough starter
4 1/2 cups bread flour
2 tsp Salt
1 Cups Warm Water
1/4 cup milk
2 TBS Honey
1 TBS Olive Oil
Place all the ingredients together in a mixer. Using a dough hook knead the dough for 10 minutes. If the dough sticks to the side of the bowl add a little flour. rub olive oil on the dough and place in a bowl. Cover the bowl with a damp towel. Let rise 2 hours. Punch down dough. Spray the inside of a large zip-lock bag, with cooking spray. Place the dough in the baggie, and put in freezer. When you want to use the dough. Take it out of the bag in the morning, and cut the bread ball into two halves. Spray a cooking sheet with oil, and dust with cornmeal. Place bread on the cookie sheet. Grease the of the dough with more olive oil. Cover the dough with plastic wrap. Then get a damp cloth to cover the cookie sheet. The plastic wrap prevents the dough from sticking to the towel. This needs to sit in the fridge for about 8 hours. It will double in size in that time. Remove plastic wrap and towels. Slash the top of each loaf several times with a sharp knife. Preheat the oven to 425F. Bake bread for 35 minutes.
How does a TV know what to display? We are going to discuss NTSC tv signals. In order to look at how an image is generated by Computer Space, we must first understand how a TV picture is composed. NTSC was develouped in 1941. It was a black and white only standard. In 1953 it was modified to allow color signals. NBC was broadcasting before 1941, using a 441 line standard. When NTSC was released it allowed for 525 lines vertically. This was a compromise other companies at the time wanted up to 800 lines. Which is more than modern SVGA monitors. All video signal must deliver 525 lines vertically. However no TV actually displays all of the lines. Each image is broken into 2 fields. Each field is half the lines of a single screen.The first field is all the odd lines, 1,3,5,…383. And the second is all the even 2,4,6,….384. This is referred to as interlacing.
This is to reduce flickering. If the image was simply drawn from top to bottom it would become noticable that it was being drawn this way. The second reason we don’t see flicker is because of the properties of phosphur. When it gets excited by the electron beam it emits light, but when the beam is shut off it doesn’t immediatly stop glowing. It slowly stops glowing. So that when the next time the beam would hit the same pixel again it isn’t completely dark yet. Helping to create the flicker free illusion.
Why don’t we get to see all 525 lines? That’s because this standard was originally concieved of using mechanical televisions. The beam of electrons scans from side to side, and then returns to the top. It was determined that it would take the equivalent of 70 lines for each field, for the beam to return to the top.
There are 646 pixels accross the screen, on the average TV This is the number of pixels that are needed in order to have the dots on the screen be square. In reality this number can vary. The television itself has small holes for each pixel. This well determine the number of pixels. However since this is a analogue signal, there can be any number of pixels. The TV will display whatever it is capable of. On very small TV’s they may only display half or a quarter of this. At he beginning of each line, there is a window of time that the line is not drawn as well, because the beam would need time to return to the other side of the screen. Reducing the maximum amount of picture that is display, this is slightly different from TV to TV as well. Because of the way crt’s work, every TV displays a slightly different number of lines on the screen. Older TV’s also drifted, so that after a while they would display different lines.
Why was NTSC designed to be 60 fields per second, or 30 frames per second. This is because of the U.S. having 60 Hertz power. TV’s could use the power frequency to make sure they don’t vary from 60 Hz. In the U.S. we actually have two seperate frequencies. The east and west parts of the country are both at 60 Hz, however they aren’t the same phase. A.C. power is alternating between 170 volts positive and 170 volts negative, 60 times per second. This power comes to us as a sine wave. To be in phase each signal has to be at positive 170 at the same time, and negative 170 at the same time. The east side of the country does not have their peak voltage of 170 at the same time as the west side. Older televisions would simply watch for when 170 volts occured, and would use this to synchronize. This is not important for this. But I simply wanted to help explain phase. Newer televisions use an oscillator to make sure they keep the proper frequency, but these were too expensive in the first tv’s. The reason for 525 lines as also because of the power frequency. It was easy to multiply and divide the frequency, and 525 is 3 × 5 × 5 × 7.
During each second their is time to draw 15750 lines. But the video truly only needs to display 11550 lines each second. This gives us 63 microseconds for each line of the screen to be displayed in. The voltage of the signal determines is black, white or a shade inbetween is display. The signal varies between 0 to 1 volts. 300mv was considered black, and one volt was white. With everything in between being shades of gray. So that for each line you would vary the voltage between .3 and 1 volts, to describe the image to the TV. There’s no pauses between pixels, which is why they are not defined for the horizontal. The display can use the voltage at any point for a pixel. If we use the 640 pixel horizontally, we see 10 pixels every 1 microsecond. Next week we’ll look at how Computer Space creates this signal.
Determining the amount of RAM in this is a little more difficult. It didn’t have ram chips, like modern machines. But instead used ttl counter chips. Inside a counter chip you have 4 flips flops wired together, to keep track of numbers 0-15. A flip flop is created by connecting together two AND gates, inverting the outputs, and connecting them back to the input. This makes a SR flip flop, or set reset flip flop. Which allows one wire to be set, making the output high or 5 volts, and the other wire would be reset, switching the output to low or 0 volts. The foundation of all memory today. This isn’t RAM, because it’s not random access memory. This is dedicated memory. When this was designed counter chips were petty common. Looking through the schematics you’ll see a number of them. The 74161, is a 4 bit counter, it will store numbers between 0 and 15. You can increment these and reset them to zero. If you connect two together, they can store numbers from 0 to 255. Which is 1 byte of memory. The 7490 is another counter it also stores 4 bits of data. Why use two different types? Probably the 74161 was a little cheaper. The 7490, was a little more capable. It could count in decimal 0-9, base 12 0-11, or hex 0-15. This chip is used so that the machine could count in decimal, this is important for display. Because most humans prefer to think in base 10. They didn’t expect anyone to get 10 points, so they didn’t implement proper display for scores over 9. Although you can get upto 15 points, it wouldn’t show properly. When you reached 16 points, you score rolled over to zero, and you started over agan. Things that the machine would need to keep track of included, the Player Ship, Computer Ship, number of deaths of each, time left to play, missles. For the player ship, we need speed x, speed y,current x, current y, and the angle of the ship. Then the missle needs x,y,and angle as well. That’s about 6 bytes. We also need that for the computer as well. Then we need one byte for the score, and 1 byte for the timer. That’s 14 bytes so far. Then we need the horizontal and vertical position that’s being sent to the tv, another 2 bytes. So this whole machine would need less than 20 bytes of memory, which would take 40 counters. Computer Space had the equivalent of 2 bytes of RAM.