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Routines |
Prev: 06133 | Up: Map |
The address of this routine is found in the parameter table.
The 'main screen' channel will need to be opened.
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LIST | 06137 | LD A,2 | Use stream 2. | |||||
This entry point is used by the routine at LLIST.
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LIST_1 | 06139 | LD (IY+2),0 | Signal 'an ordinary listing in the main part of the screen' (reset bit 4 of TV-FLAG and all other bits). | |||||
06143 | CALL SYNTAX_Z | Open the channel unless checking syntax. | ||||||
06146 | CALL NZ,CHAN_OPEN | |||||||
06149 | RST 24 | With the present character in the A register see if the stream is to be changed. | ||||||
06150 | CALL STR_ALTER | |||||||
06153 | JR C,LIST_4 | Jump forward if unchanged. | ||||||
06155 | RST 24 | Is the present character a ';'? | ||||||
06156 | CP ";" | |||||||
06158 | JR Z,LIST_2 | Jump if it is. | ||||||
06160 | CP "," | Is it a ','? | ||||||
06162 | JR NZ,LIST_3 | Jump if it is not. | ||||||
LIST_2 | 06164 | RST 32 | A numeric expression must follow, e.g. LIST #5,20. | |||||
06165 | CALL CLASS_06 | |||||||
06168 | JR LIST_5 | Jump forward with it. | ||||||
LIST_3 | 06170 | CALL USE_ZERO | Otherwise use zero and also jump forward. | |||||
06173 | JR LIST_5 | |||||||
Come here if the stream was unaltered.
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LIST_4 | 06175 | CALL FETCH_NUM | Fetch any line or use zero if none supplied. | |||||
LIST_5 | 06178 | CALL CHECK_END | If checking the syntax of the edit-line move on to the next statement. | |||||
06181 | CALL FIND_INT2 | Line number to BC. | ||||||
06184 | LD A,B | High byte to A. | ||||||
06185 | AND 63 | Limit the high byte to the correct range and pass the whole line number to HL. | ||||||
06187 | LD H,A | |||||||
06188 | LD L,C | |||||||
06189 | LD (23625),HL | Set E-PPC and find the address of the start of this line or the first line after it if the actual line does not exist. | ||||||
06192 | CALL LINE_ADDR | |||||||
This entry point is used by the routine at AUTO_LIST.
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LIST_ALL | 06195 | LD E,1 | Flag 'before the current line'. | |||||
Now the controlling loop for printing a series of lines is entered.
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LIST_ALL_1 | 06197 | CALL OUT_LINE | Print the whole of a BASIC line. | |||||
06200 | RST 16 | This will be a 'carriage return'. | ||||||
06201 | BIT 4,(IY+2) | Jump back unless dealing with an automatic listing (bit 4 of TV-FLAG set). | ||||||
06205 | JR Z,LIST_ALL_1 | |||||||
06207 | LD A,(23659) | Also jump back if there is still part of the main screen that can be used (DF-SZ <> S-POSN-hi). | ||||||
06210 | SUB (IY+79) | |||||||
06213 | JR NZ,LIST_ALL_1 | |||||||
06215 | XOR E | A return can be made at this point if the screen is full and the current line has been printed (E=0). | ||||||
06216 | RET Z | |||||||
06217 | PUSH HL | However if the current line is missing from the listing then S-TOP has to be updated and a further line printed (using scrolling). | ||||||
06218 | PUSH DE | |||||||
06219 | LD HL,23660 | |||||||
06222 | CALL LN_FETCH | |||||||
06225 | POP DE | |||||||
06226 | POP HL | |||||||
06227 | JR LIST_ALL_1 |
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