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1345
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1 **************************************************
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2 * System Call: F$MapBlk
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3 *
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4 * Function: Map specific block
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5 *
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6 * Input: B = Number of blocks
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7 * X = Beginning block number
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8 *
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9 * Output: U = Address of first block
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10 *
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11 * Error: CC = C bit set; B = error code
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12 *
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1145
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13 FMapBlk lda R$B,u get # blocks
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14 beq L0BAA can't map 0 blocks, return error
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15 cmpa #DAT.BlCt within range of DAT image?
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16 bhi L0BAA no, return error
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17 leas -$10,s make a buffer to hold DAT image
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18 ldx R$X,u get start block #
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19 ldb #1 block increment value
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1245
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20 IFNE H6309
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1145
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21 * Change to W 05/19/93 - used W since one cycle faster per block
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22 tfr s,w point to buffer
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23 FMapBlk2 stx ,w++ save block # to buffer
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1245
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24 ELSE
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25 tfr s,y point to buffer
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26 FMapBlk2 stx ,y++ save block # to buffer
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27 ENDC
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1145
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28 abx Next block
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29 deca done?
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30 bne FMapBlk2 no, keep going
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31 ldb R$B,u get block count again
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32 ldx <D.Proc get process pointer
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33 leay <P$DATImg,x point to DAT image
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34 os9 F$FreeHB find the highest free block offset
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35 bcs L0BA6 no room, return error
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1245
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36 IFNE H6309
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1145
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37 tfr d,w Preserve start block # & # of blocks
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1245
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38 ELSE
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39 pshs d
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40 ENDC
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1145
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41 lsla Multiply start block # by 32
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42 lsla
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43 lsla
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44 lsla
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45 lsla
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46 clrb
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47 std R$U,u save address of first block
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1245
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48 IFNE H6309
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1145
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49 tfr w,d Restore offset
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1245
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50 ELSE
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51 puls d
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52 ENDC
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1145
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53 leau ,s move DAT image into process descriptor
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54 os9 F$SetImg Change process dsc to reflect new blocks
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55 L0BA6 leas <$10,s Eat DAT image copy & return
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56 rts
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57
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58 L0BAA comb Illegal Block address error
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59 ldb #E$IBA
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60 rts
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