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The address of this routine is found in the parameter table.
The 'main screen' channel will need to be opened.
LIST 06137 LD A,2 Use stream 2.
This entry point is used by the routine at LLIST.
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.
06149 RST 24 With the present character in the A register see if the stream is to be changed.
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.
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.
This entry point is used by the routine at AUTO_LIST.
LIST_ALL 06195 LD E,1 Flag 'before the current line'.
Now the controlling loop for printing a series of lines is entered.
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
06225 POP DE
06226 POP HL
06227 JR LIST_ALL_1
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