Add missing file about the .dat / PTCR file

PTCR.md

@@ -0,0 +1,169 @@
+PTCR File:
+==========
+
+ ## Basic structure
+
+```
+struct PTCRFile:
+    struct Header:
+        char[4]  = "PTCR"
+        uint32_t version
+        uint32_t numberOfCommands (only drawable commands?)
+        uint32_t fileSize - Header
+        char[12]: unknown
+        char[4] = 0xAA, 0x55, 0xAA, 0x55
+
+    char[]: data
+```
+
+Data contain commands that correspond to all the action that can be done on the MB701.
+
+Each command start with an opcode, then a couple of bytes following depending on the opcode
+
+In each drawing command, the _stoke number_ (byte 1 and byte 2) seems to be sequentially increasing.
+
+ ## Commands
+
+ ### F0: drawPixels
+
+| byte 0 | byte 1    | byte 2    | byte 3      | byte 4  | byte 5  | byte x     |
+| ------ |-----------|-----------|-------------|---------|---------|------------|
+| F0     | Stroke #1 | Stroke #2 | Pixel count | Start X | Start Y | Pixel data |
+
+ #### Notes
+ - Start position X and Y are stored *4 their real value
+ - The count of pixel data is `(pixel count - 1) / 2`
+
+Each addition pixel are calculated relative with the last drawn pixel.
+Each byte store the position of two pixels, b0-b3 for the first pixel, b4-b7 for the second, if the number of pixels is odd, the last b4-b7 is ignored and should be zero.
+
+The number you get give the direction to move the pixel according to that diagram:
+```
+X ------->
+Y  1      2      3
+|  4    Origin   6
+|  7      8      9
+V
+```
+5 is ignored as it is the origin.
+
+*All other value are treated like 5 and ignored.*
+
+ #### Examples
+ - `F0 0A 14 01 34 40`: 1 pixel at [13;16]
+ - `F0 0A 11 05 30 4C 66 66`: 5 pixels at [12;19], [13;19], [14;19], [15;19], [16;19]
+
+
+ ### F1: drawLine
+
+| byte 0 | byte 1    | byte 2    | byte 3 | byte 4 | byte 5 | byte 6 | byte 7 |
+|--------|-----------|-----------|--------|--------|--------|--------| ------ |
+| F1     | Stroke #1 | Stroke #2 | ???    | x0     | y0     | x1     | y1     |
+
+A line is drawn between [x0;y0] and [x1; y1]
+
+ #### Examples:
+ - `F1 0A 0E 02 38 20 58 10`: Will draw a line 
+
+
+ ### F2: drawCircle
+
+| byte 0 | byte 1    | byte 2    | byte 3 | byte 4 | byte 5 | byte 6 | byte 7 |
+|--------|-----------|-----------|--------|--------|--------|--------| ------ |
+| F2     | Stroke #1 | Stroke #2 | ???    | x0     | y0     | x1     | y1     |
+
+The circle is drawn in the rectangle designed by [x0;y0] - [x1; y1]
+
+ #### Examples:
+ - `F2 0A 55 02 34 24 54 44`
+ - `F2 0A 57 02 50 24 50 24`
+
+
+ ### F3: Not used
+ ### F4: Not used
+
+
+ ### F5: replaceColor
+| byte 0 | byte 1    | byte 2    | byte 3    | byte 4         |
+|--------|-----------|-----------|-----------|----------------|
+| F5     | Stroke #1 | Stroke #2 | New color | Replaced color |
+
+ #### Examples:
+ - `F5 0A 5B 5B 5F`
+ - `F5 0A 7B 2A 5B`
+
+
+ ### F6: erasePixel (?)
+
+| byte 0 | byte 1    | byte 2    | byte 3      | byte 4  | byte 5  | byte x     |
+|--------|-----------|-----------|-------------|---------|---------|------------|
+| F6     | Stroke #1 | Stroke #2 | Pixel count | Start X | Start Y | Pixel data |
+
+*Work like F0, but erase pixel instead of drawing, see F0 for the format*
+
+
+ ### F7: clearCanvas
+
+| byte 0 | byte 1    | byte 2    | byte 3                 |
+|--------|-----------|-----------|------------------------|
+| F7     | Stroke #1 | Stroke #2 | ??? (Color to clear?)  |
+
+Code clear the canvas to all white whatever the value. Not sure what the byte 3 is suppose to represent.
+
+ #### Examples:
+ - `F7 0C 4B 00`
+ - `F7 16 2E 00`
+
+
+ ### F8: Not used
+ ### F9: Not used
+
+
+ ### FA: setColor
+| byte 0 | byte 1    | byte 2 |
+|--------|-----------|--------|
+| FA     | new color | ???    |
+
+ #### examples:
+ - `FA 67 6A` : now work with colour 0x67
+ - `FA 20 67` : now work with colour 0x20
+
+
+ ### FB: setCanvasResolution
+| byte 0 | byte 1          | byte 2        |
+|--------|-----------------|---------------|
+| FB     | horizontal size | vertical size |
+
+_If the value is not 16, 24 or 32 it will default back to 16_
+
+
+ ### FC: Not used
+ ### FD: Not used
+ ### FE: Not used
+ ### FF: Not used
+
+
+## How stroke number work:
+
+For some reason 0 is represented by 0x0A (10) 0x0A. 
+When the number of storke is increased the second byte is incremented by 1. 
+Then when the second byte reach 0x9F (159) the first one will be incremented and the
+second byte reset to 0x0A.
+
+
+Example:
+
+
+| Hex   | Binary              | Decilam |
+|-------|---------------------|---------|
+| 0A 0A | 0000 1010 0000 1010 | 10  10  |
+| ...   |                     |         |
+| 0A 9F | 0000 1010 1001 1111 | 10  159 |
+| 0B 0A | 0000 1011 0000 1010 | 11  10  |
+| ...   |                     |         |
+| 0B 9F | 0000 1011 1001 1111 | 11  159 |
+| 0C 0A | 0000 1100 0000 1010 | 12  10  |
+| ...   |                     |         |
+| 18 89 | 0001 1000 1000 1001 | 24  137 |
+
+_Why does it work this way? Your guess is as good as mine._