Color64

Color64 is a computer BBS system that was very popular for the Commodore 64 during the 1980s. It was written by Greg Pfountz. Color64 was advanced for its time. The I/O was all written in machine language. It was also composed in modules, each written in BASIC. Each module would be loaded into memory as a user went from one part of the system to another. For example, the login module was what handled the answering of the phone and the verification of login info. It would then load the main menu module. Going into the message boards would load the message board module. Online games worked the same way.

Because the Commodore 1541 and Commodore 1571 disk drives were slow, most BBSs would use memory expansion module. This would serve as a RAM disk and allow all modules to be loaded quickly.

Color

Color (American English) or colour (Commonwealth English) is the visual perceptual property corresponding in humans to the categories called red, blue, yellow, etc. Color derives from the spectrum of light (distribution of light power versus wavelength) interacting in the eye with the spectral sensitivities of the light receptors. Color categories and physical specifications of color are also associated with objects or materials based on their physical properties such as light absorption, reflection, or emission spectra. By defining a color space colors can be identified numerically by their coordinates.

Because perception of color stems from the varying spectral sensitivity of different types of cone cells in the retina to different parts of the spectrum, colors may be defined and quantified by the degree to which they stimulate these cells. These physical or physiological quantifications of color, however, do not fully explain the psychophysical perception of color appearance.

The science of color is sometimes called chromatics, colorimetry, or simply color science. It includes the perception of color by the human eye and brain, the origin of color in materials, color theory in art, and the physics of electromagnetic radiation in the visible range (that is, what we commonly refer to simply as light).

Greeks (finance)

In mathematical finance, the Greeks are the quantities representing the sensitivity of the price of derivatives such as options to a change in underlying parameters on which the value of an instrument or portfolio of financial instruments is dependent. The name is used because the most common of these sensitivities are denoted by Greek letters (as are some other finance measures). Collectively these have also been called the risk sensitivities,risk measures or hedge parameters.

Use of the Greeks

The Greeks are vital tools in risk management. Each Greek measures the sensitivity of the value of a portfolio to a small change in a given underlying parameter, so that component risks may be treated in isolation, and the portfolio rebalanced accordingly to achieve a desired exposure; see for example delta hedging.

The Greeks in the Black–Scholes model are relatively easy to calculate, a desirable property of financial models, and are very useful for derivatives traders, especially those who seek to hedge their portfolios from adverse changes in market conditions. For this reason, those Greeks which are particularly useful for hedging—such as delta, theta, and vega—are well-defined for measuring changes in Price, Time and Volatility. Although rho is a primary input into the Black–Scholes model, the overall impact on the value of an option corresponding to changes in the risk-free interest rate is generally insignificant and therefore higher-order derivatives involving the risk-free interest rate are not common.

Color (manga)

Color is a Japanese manga anthology written and illustrated by Taishi Zaou and Eiki Eiki. Color was serialized in Dear+, a magazine known for its romantic and non-explicit boys love manga published by Shinshokan, and a tankōbon collecting the chapters released in February 1999.Color is licensed in North America by Digital Manga Publishing which released the manga in June 2009. It is licensed in France by Asuka and in Germany by Egmont Manga.

Reception