ASSEMBLY LANGUAGE EXAMPLES |
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Example 1 |
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| LD HL, 22528 | 210058 | Start of the attributes |
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| LD DE, 30100 | 119475 | Storage byte |
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| LD A, 22 | 3E16 | Loop counter |
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ONE |
LD (DE), A | 12 | Stored at 30100 |
| LD B, 32 | 0620 | Column counter |
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TWO |
LD (HL), 127 | 367F | Attribute value |
| INC HL | 23 | placed in row |
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| DJNZ TWO | 10FB | ||
| LD A, (DE) | 1A | Recover loop counter |
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| LD B, A | 47 | Copy in B |
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| DEC A | 3D | Loop counter minus one |
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| LD (DE), A | 12 | Replace loop counter |
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| DJNZ ONE | 10F3 | Jump back to ONE |
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| RET | C9 | unless all done |
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Example 2 |
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This is the same as 1 except for the first three lines |
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| LD HL, 16384 | 210040 | Start of display file |
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| LD DE, 30100 | 119475 | Storage byte |
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| LD A, 200 | 3EC8 | Loop counter |
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Example 3 |
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| LD HL, 22528 | 210058 | Start of the attributes |
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| LD DE, 30100 | 119475 | Storage byte |
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| LD A, 6 | 3E06 | First loop counter |
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| LD (DE), A | 12 | stored |
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| LD A, 0 | 3E00 | Attribute value |
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| LD (30101), A | 329575 | stored |
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ONE | LD A, (30101) | 3A9575 | Recover attribute value |
| LD B, 128 | 0680 | Loop counter |
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TWO | LD (HL), A | 77 | Place attribute in file |
| INC HL | 23 | next position |
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| DJNZ TWO | 10FC | until 128 done |
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| LD B, 8 | 0608 | Add eight |
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TRE | INC A | 3C | to attribute value |
| DJNZ TRE | 10FD | ||
| LD (30101), A | 329575 | Store new value |
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| LD A, (DE) | 1A | Recover counter |
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| LD B, A | 47 | Copy into B |
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| DEC A | 3D | Counter minus one |
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| LD (DE), A | 12 | Store new counter value |
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| DJNZ ONE | 10EB | Jump back to ONE |
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| RET | C9 | unless B = 0 |
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