mirror of https://github.com/option8/gp2io.git
33 lines
4.8 KiB
Plaintext
33 lines
4.8 KiB
Plaintext
------+----------------------+-------------+----+---------+------+-----------------------+-------------------------------------------------------------------
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Line | # File Line | Line Type | MX | Reloc | Size | Address Object Code | Source Code
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------+----------------------+-------------+----+---------+------+-----------------------+-------------------------------------------------------------------
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1 | 1 sendbyte.s 1 | Directive | 11 | | 0 | 00/8000 | ORG $0300
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2 | 1 sendbyte.s 2 | Equivalence | 11 | | 0 | 00/0300 | ANN0HI EQU $C059
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3 | 1 sendbyte.s 3 | Equivalence | 11 | | 0 | 00/0300 | ANN0LO EQU $C058
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4 | 1 sendbyte.s 4 | Equivalence | 11 | | 0 | 00/0300 | ANN1HI EQU $C05B
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5 | 1 sendbyte.s 5 | Equivalence | 11 | | 0 | 00/0300 | ANN1LO EQU $C05A
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6 | 1 sendbyte.s 6 | Equivalence | 11 | | 0 | 00/0300 | BYTETOSEND EQU $EF
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7 | 1 sendbyte.s 7 | Empty | 11 | | 0 | 00/0300 |
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8 | 1 sendbyte.s 8 | Code | 11 | | 2 | 00/0300 : A0 08 | SENDBYTE LDY #$08 ; load 8 for a full byte, loop counter
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9 | 1 sendbyte.s 9 | Code | 11 | | 2 | 00/0302 : 85 EF | STA {$EF} ; put byte in zero page for safe keeping
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10 | 1 sendbyte.s 10 | Code | 11 | | 3 | 00/0304 : 8D 59 C0 | RTS STA {$C059} ; annunciator 0 high, RTS
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11 | 1 sendbyte.s 11 | Code | 11 | | 2 | 00/0307 : 26 EF | SENDBIT ROL {$EF} ; rotate byte left, high/MSB out to carry (sendbit)
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12 | 1 sendbyte.s 12 | Code | 11 | | 2 | 00/0309 : 90 05 | BCC SHORTLOOP ; "branch on carry clear" - if carry/bit = 0, goto #311 (short loop)
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13 | 1 sendbyte.s 13 | Code | 11 | | 2 | 00/030B : A2 14 | LONGLOOP LDX #$14 ; if carry/bit = 1, load X with 20 (long loop)
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14 | 1 sendbyte.s 14 | Code | 11 | | 3 | 00/030D : 4C 12 03 | JMP SETANN1 ; jump over SHORTLOOP
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15 | 1 sendbyte.s 15 | Code | 11 | | 2 | 00/0310 : A2 0A | SHORTLOOP LDX #$0A ; if carry/bit = 0, load X with 10 (short loop)
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16 | 1 sendbyte.s 16 | Code | 11 | | 3 | 00/0312 : 8D 5B C0 | SETANN1 STA {$C05B} ; set annunciator 1 HIGH
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17 | 1 sendbyte.s 17 | Code | 11 | | 1 | 00/0315 : CA | COUNTDOWN DEX ; decrement, countdown to setting ANN1 low (COUNTDOWN)
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18 | 1 sendbyte.s 18 | Code | 11 | | 2 | 00/0316 : D0 FD | BNE COUNTDOWN ; if X > 0, keep counting (goto COUNTDOWN)
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19 | 1 sendbyte.s 19 | Code | 11 | | 3 | 00/0318 : 8D 5A C0 | STA {$C05A} ; if done, set ANN1 LOW, countdown to getting next bit
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20 | 1 sendbyte.s 20 | Code | 11 | | 2 | 00/031B : A2 05 | LDX #$05 ; reset counter for short "reset" transition. This lets the GP2IO stage the bit before the next interrupt
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21 | 1 sendbyte.s 21 | Code | 11 | | 1 | 00/031D : CA | COUNTDOWN2 DEX ; count down again (COUNTDOWN2)
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22 | 1 sendbyte.s 22 | Code | 11 | | 2 | 00/031E : D0 FD | BNE COUNTDOWN2 ; if X > 0, keep counting (goto COUNTDOWN2)
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23 | 1 sendbyte.s 23 | Code | 11 | | 1 | 00/0320 : 88 | DEY ; decrement y, countdown bits sent
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24 | 1 sendbyte.s 24 | Code | 11 | | 2 | 00/0321 : D0 E4 | BNE SENDBIT ; if y > 0, next bit (SENDBIT)
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25 | 1 sendbyte.s 25 | Code | 11 | | 3 | 00/0323 : 8D 58 C0 | RTSOFF STA {$C058} ; annunciator 0 low, sending RTS OFF
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26 | 1 sendbyte.s 26 | Code | 11 | | 1 | 00/0326 : 60 | RTS ; return
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27 | 1 sendbyte.s 27 | Empty | 11 | | 0 | 00/0327 |
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28 | 1 sendbyte.s 28 | Empty | 11 | | 0 | 00/0327 |
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------+----------------------+-------------+----+---------+------+-----------------------+-------------------------------------------------------------------
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