PS$
'' specifies on
which file the output should go. Beware that the variable cannot be
changed from within PCSCHEME. This is a strange behaviour I don't really
care to deal with; but it is due to duplication of the environment.
PS accepts a wide variety of display modes, because the Postscript language is by nature pixel-independent while BGI is pixel-oriented; and the lines' width, points' size etc. are determined by the device's resolution. There are 6 normal modes, and 6 encapsulated modes. The former create output ready to send to a printer, while the latter are best suited to create images to be inserted in a document.
There is an eternal problem with color and display versus hardcopy. The colors are not changed, but the greytones are swapped. This is logical since a screen is black by default, while a blank sheet of paper is white. The driver accepts the same color requests as a SUPER-VGA card: 16 colors by default and a user-settable 256-entry palette. Here are the first preset 16 colors:
Index | Color | Red | Green | Blue |
0 | White | 100% | 100% | 100% |
1 | Dark Blue | 0% | 0% | 50% |
2 | Dark Green | 0% | 50% | 0% |
3 | Dark Cyan | 0% | 50% | 50% |
4 | Dark Red | 50% | 0% | 0% |
5 | Dark Magenta | 50% | 0% | 50% |
6 | Dark Brown | 50% | 50% | 0% |
7 | Dark Grey | 50% | 50% | 50% |
8 | Light Grey | 75% | 75% | 75% |
9 | Blue | 0% | 0% | 100% |
10 | Green | 0% | 100% | 0% |
11 | Cyan | 0% | 100% | 100% |
12 | Red | 100% | 0% | 0% |
13 | Magenta | 100% | 0% | 100% |
14 | Brown | 100% | 100% | 0% |
15 | Black | 0% | 0% | 0% |
There are no restrictions nor royalties associated to the use, distibution or modification of PS and SPY.