This allowed the Computer Hobbyist or 3rd-party companies to create after-market field modifications, such as increased clock speed, increasing the cassette tape drive storage speed, and increased video line length, as well as reverse video ( white screen with black text ).
12.
The display was a 24-line, 80-character ( 7?0 dot matrix ) white-on-black monochrome CRT, with software-selectable variations such as reverse video, blinking, low-intensity ( equivalent to grey text ), and 4?-resolution graphics.
13.
If the high-order bit is set on a character ( i . e ., if the byte value of the character is between 128 and 255 ) the character is generally rendered in the reverse video ( also called " inverse video " ) of its counterpart between 0 and 127, using a bitwise negation of the character's glyph.
14.
The first line has a line number of 0 or 1 ( indicating the drive number ), showing in reverse video the name and ID of the disk and a shorthand code for the DOS version with which it was created ( codes vary only as far as the DOS versions use incompatible disk formats, " 2A " is used by most 5.25 inch DOS versions, " 3D " by the 3.5 inch 1581 ).
15.
Later models included " base colour " support for four colours . " In base color mode, the protection and intensity bits are used in combination to select among four colors : normally white, red, blue, and green; the protection bits retain their protection functions as well as determining color . " Still later models used " extended attributes " to add support for seven colours, blinking, reverse video, underscoring, field outlining, field validation, and programmed symbols.
16.
This type of software usually enables the trader to assemble the relevant information into composite pages, comprising a news panel, in text format, sliding in real time from bottom to top, a quotes panel, for instance spot rates against the US dollar, every quote update or ?tick ?showing up in reverse video during one or two seconds, a graphical analysis panel, with moving averages, MACD, candlesticks or other technical indicators, another panel that displays competitive quotes from different brokers, etc . ..
