Thanks to Julio Marchi for this space in MSX All
 

Aquarela (.SPR), (.FNT) and (.PRD)

  The sprites (.SPR) and fonts (.FNT) files are identical. They are formed by picture blocks of 16x16 pixels that follow the same MSX sprite pattern. Each picture takes 32 bytes.
  The file is composed by the MSX file header and the 16x16 pictures stacked. Both file types have predefined sizes.
  The sprite file has up to 64 pictures and 2048 bytes size. Thus, Aquarela shows only 32 pictures at time (page #1 and #2). In fact, this is a MSX sprite pattern table dump.
  File .SPR
 ┌────────┬───────────┬───────────┬───────────┬────────────┐
 │ Header │ Picture 1 │ Picture 2 │   ...     │ Picture 64 │
 └────────┴───────────┴───────────┴───────────┴────────────┘

  The font file has 46 pictures and 1473 bytes size. Nevertheless, only 1472 bytes are used by the pictures.
  File .FNT
 ┌────────┬───────────┬───────────┬───────────┬────────────┐
 │ Header │ Picture 1 │ Picture 2 │   ...     │ Picture 46 │
 └────────┴───────────┴───────────┴───────────┴────────────┘

  Sprites pattern

  Each byte defines a 1x8 pixels line, where the value "1" turns on the pixels, while the value "0" turns off the pixel. The 32 lines layout is described as follows:
 line 1    line 17
 line 2    line 18
 line 3    line 19
 line 4    line 20
 line 5    line 21
 line 6    line 22
 line 7    line 23
 line 8    line 24

 line 9    line 25
 line 10   line 26
 line 11   line 27
 line 12   line 28
 line 13   line 29
 line 14   line 30
 line 15   line 31
 line 16   line 32

  The pattern file (.PRD) has 16 pictures of 8x8 pixels which are used as fill pattern. Notice that in Aquarela they are draw as 16x16 blocks when the pattern menu is accessed.
  This file has the MSX file header followed by the data. The data takes 128 bytes, and they start at file offset &H67.


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