Routines
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07558: THE 'LOOK-PROG' SUBROUTINE
Used by the routines at FOR, READ_3 and S_FN_SBRN.
This subroutine is used to find occurrences of either DATA, DEF FN or NEXT.
Input
E Token code to search for
HL Search start address
Output
F Carry flag reset if the token is found
LOOK_PROG 07558 LD A,(HL) Fetch the present character.
07559 CP ":" Jump forward if it is a ':', which will indicate there are more statements in the present line.
07561 JR Z,LOOK_P_2
Now a loop is entered to examine each further line in the program.
LOOK_P_1 07563 INC HL Fetch the high byte of the line number and return with carry set if there are no further lines in the program.
07564 LD A,(HL)
07565 AND 192
07567 SCF
07568 RET NZ
07569 LD B,(HL) The line number is fetched and passed to NEWPPC.
07570 INC HL
07571 LD C,(HL)
07572 LD (23618),BC
07576 INC HL Then the length is collected.
07577 LD C,(HL)
07578 INC HL
07579 LD B,(HL)
07580 PUSH HL The pointer is saved whilst the address of the end of the line is formed in the BC register pair.
07581 ADD HL,BC
07582 LD B,H
07583 LD C,L
07584 POP HL The pointer is restored.
07585 LD D,0 Set the statement counter to zero.
LOOK_P_2 07587 PUSH BC The end-of-line pointer is saved whilst the statements of the line are examined.
07588 CALL EACH_STMT
07591 POP BC
07592 RET NC Make a return if there was an 'occurrence'; otherwise consider the next line.
07593 JR LOOK_P_1
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