42 lines
1.2 KiB
Nim
42 lines
1.2 KiB
Nim
import vga
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const
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vgaWidth = 80
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vgaHeight = 25
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terminalBufferBaseAddress = 0xB8000
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bufferWidthSkip = vgaWidth * 2
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var
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terminalRow, terminalColumn = 0
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terminalColour: int
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proc terminalWriteAtPoint(writeChar: char, colour: int, xPos: int, yPos: int) =
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let index = terminalBufferBaseAddress + (yPos * bufferWidthSkip + (xPos * 2))
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cast[ptr int16](index)[] = vga.vgaEntry(writeChar, terminalColour) # Write directly to display memory
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proc terminalInitialize*() =
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terminalColour = vgaEntryColour(VGA_Colour.lightGreen, VGA_Colour.red)
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for x in 0..<vgaWidth:
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for y in 0..<vgaHeight:
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terminalWriteAtPoint(' ', terminalColour, x, y)
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proc setTerminalColour(newColour: int) =
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terminalColour = newColour
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proc terminalWriteChar(writeChar: char) =
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if(writeChar == '\L'):
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inc(terminalRow)
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terminalColumn = 0
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if(terminalRow == vgaHeight): terminalRow = 0
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return
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terminalWriteAtPoint(writeChar, terminalColour, terminalColumn, terminalRow)
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inc(terminalColumn)
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if(terminalColumn == vgaWidth):
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terminalColumn = 0
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inc(terminalRow)
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if(terminalRow == vgaHeight): terminalRow = 0
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proc terminalWrite*(data: string) =
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for character in data:
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terminalWriteChar(character)
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