Thanks to Julio Marchi for this space in MSX All
 

Print Master (.PM?)

  Four files compose a 512 x 768 screen size, where each file is responsible for storing an area clip of 512 x 192 pixels. They are stocked vertically, as depicted below:

 

  Screen layout

  Each .PM file is based on the MSX 1 character map format, which composes the monochromatic picture.

  The screen is composed by 8x8 pixel blocks, where one byte represents a line. In this line, each bit represents a pixel, where the value 1 represents the pixel on, while the value 0 represents the pixel off, as seen on the picture below.

┌─┬─┬─┬─┬─┬─┬─┬─┐
│X│ │X│ │ │ │ │ │ Linha 0 - Binary value: 10100000
├─┼─┼─┼─┼─┼─┼─┼─┤
│ │ │ │ │ │ │ │X│ Linha 1 - Binary value: 00000001
├─┼─┼─┼─┼─┼─┼─┼─┤
│ │ │ │ │ │ │ │ │ Linha 2
├─┼─┼─┼─┼─┼─┼─┼─┤
│ │ │ │ │ │ │ │ │ Linha 3
├─┼─┼─┼─┼─┼─┼─┼─┤
│ │ │ │ │ │ │ │ │ Linha 4
├─┼─┼─┼─┼─┼─┼─┼─┤
│ │ │ │ │ │ │ │ │ Linha 5
├─┼─┼─┼─┼─┼─┼─┼─┤
│ │ │ │ │ │ │ │ │ Linha 6
├─┼─┼─┼─┼─┼─┼─┼─┤
│ │ │ │ │ │ │ │ │ Linha 7
└─┴─┴─┴─┴─┴─┴─┴─┘

  For a 512 x 192 pixels screen, the 8x8 blocks are configured as follows:

 0  1  2  3 ...  63
64 65 66 67 ... 127
...

  Using the pseudo-algorithm for MSX screens, set width equal to 512.
  The .PM file has no MSX file header.


Marcelo Silveira
Systems and Computing Engineer
Expert in Image Processing and Artificial Intelligence
© MarMSX 1999-2021