Drawing & Display

Instructions in this category draw graphics and output numbers or text on the display.

Every coordinate is an 8-bit value (00~FF), written in hexadecimal in the program. Coordinates are shifted by an offset and converted by the MCU into commands for the main screen. Shapes are drawn with the pen color taken from the drawing-color register, and the text background follows the background-color register.

0x55 Display Number (SC)

Display the value of a register at the given position, formatted as a decimal number with optional decimal places.

Instruction Form

000  10  000A  0064    R10 = 100
001  55  280A  0A01    show R10 at (40,10) with 1 decimal place

Mnemonic Form

000  FZ  000A  0064    R10 = 100
001  SC  280A  0A01    show R10 at (40,10) with 1 decimal place

The value is divided by 10ⁿ before display: with one decimal place, 100 is shown as 10.0.

info

Operands	Value/Range	Remark
OP-00	00~FF	X coordinate
OP-01	00~FF	Y coordinate
OP-10	00~FF	Source register holding the value
OP-11	00~FF	Low 4 bits: number of decimal places n (displayed as value/10ⁿ); high 4 bits: fixed display length

note

The format of OP-11 (decimal places / fixed length) is pending on-hardware verification.

0x56 Display Text (WZ)

Display ASCII characters read from consecutive memory starting at a register.

Instruction Form

000  10  0014  4849    R20 = "HI" (48 49 hex)
001  56  0000  1402    show 2 chars from R20 at (0,0)

Mnemonic Form

000  FZ  0014  4849    R20 = "HI" (48 49 hex)
001  WZ  0000  1402    show 2 chars from R20 at (0,0)

Characters are read byte by byte starting at the register given in OP-10: high byte of R[n], low byte of R[n], high byte of R[n+1], and so on. In the example, H (48) is stored in the high byte and I (49) in the low byte of R20.

info

Operands	Value/Range	Remark
OP-00	00~FF	X coordinate
OP-01	00~FF	Y coordinate
OP-10	00~FF	Starting register number
OP-11	01~10	Number of characters, at most 16

0x57 Draw Circle (YX)

Draw a hollow circle with the specified center and radius.

Instruction Form

000  57  7070  0A00    hollow circle, center (112,112), radius 10

Mnemonic Form

000  YX  7070  0A00    hollow circle, center (112,112), radius 10

info

Operands	Value/Range	Remark
OP-00	00~FF	Circle center X coordinate
OP-01	00~FF	Circle center Y coordinate
OP-10	00~FF	Radius
OP-11	00	Ignored

0x58 Draw Filled Circle (YXTC)

Draw a filled circle with the specified center and radius.

Instruction Form

000  58  7070  0A00    filled circle, center (112,112), radius 10

Mnemonic Form

000  YXTC  7070  0A00    filled circle, center (112,112), radius 10

info

Operands	Value/Range	Remark
OP-00	00~FF	Circle center X coordinate
OP-01	00~FF	Circle center Y coordinate
OP-10	00~FF	Radius
OP-11	00	Ignored

0x59 Draw Rectangle (JX)

Draw a hollow rectangle with the specified diagonal vertices.

Instruction Form

000  59  3030  5580    hollow rectangle, (48,48) to (85,128)

Mnemonic Form

000  JX  3030  5580    hollow rectangle, (48,48) to (85,128)

info

Operands	Value/Range	Remark
OP-00	00~FF	Vertex X0 coordinate
OP-01	00~FF	Vertex Y0 coordinate
OP-10	00~FF	Vertex X1 coordinate
OP-11	00~FF	Vertex Y1 coordinate

0x5A Draw Filled Rectangle (JXTC)

Draw a filled rectangle with the specified diagonal vertices.

Instruction Form

000  5A  1010  2020    filled rectangle, (16,16) to (32,32)

Mnemonic Form

000  JXTC  1010  2020    filled rectangle, (16,16) to (32,32)

The width of the rectangle is x1−x0 and the height is y1−y0.

info

Operands	Value/Range	Remark
OP-00	00~FF	Vertex X0 coordinate
OP-01	00~FF	Vertex Y0 coordinate
OP-10	00~FF	Vertex X1 coordinate
OP-11	00~FF	Vertex Y1 coordinate

0x5B Draw Line (HX)

Draw a straight line between two specified points.

Instruction Form

000  5B  6060  2020    line from (96,96) to (32,32)

Mnemonic Form

000  HX  6060  2020    line from (96,96) to (32,32)

info

Operands	Value/Range	Remark
OP-00	00~FF	Endpoint 1 X coordinate
OP-01	00~FF	Endpoint 1 Y coordinate
OP-10	00~FF	Endpoint 2 X coordinate
OP-11	00~FF	Endpoint 2 Y coordinate