18 lines
424 B
QBasic
18 lines
424 B
QBasic
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10 REM Test CGA graphics framebuffer PEEK/POKE
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20 SCREEN 1
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30 DEF SEG = &HB800
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40 REM POKE a byte at offset 0 (even row 0, first 4 pixels)
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50 POKE 0, &HFF
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60 V = PEEK(0)
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70 PRINT "POKE FF PEEK="; V
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80 REM POKE at odd row bank (offset 0x2000)
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90 POKE &H2000, &HAA
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100 V = PEEK(&H2000)
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110 PRINT "ODD ROW PEEK="; V
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120 REM Clear and verify
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130 POKE 0, 0
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140 PRINT "CLEARED="; PEEK(0)
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150 SCREEN 0
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160 DEF SEG
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170 PRINT "DONE"
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