| Routines

06651: THE 'E-LINE-NO' SUBROUTINE

Used by the routines at MAIN_EXEC and LINE_SCAN. This subroutine is used to read the line number of the line in the editing area. If there is no line number, i.e. a direct BASIC line, then the line number is considered to be zero.
Output
BC | Number of the line in the editing area (or 0 if none)
E_LINE_NO | 06651 | LD HL,(23641) | Pick up the pointer to the edit-line (E-LINE).
| 06654 | DEC HL | Set CH-ADD to point to the location before any number.
| 06655 | LD (23645),HL
| 06658 | RST 32 | Pass the first code to the A register.
| 06659 | LD HL,23698 | However before considering the code make the calculator's memory area a temporary calculator stack area (by setting STKEND equal to MEMBOT).
| 06662 | LD (23653),HL
| 06665 | CALL INT_TO_FP | Now read the digits of the line number. Return zero if no number exists.
| 06668 | CALL FP_TO_BC | Compress the line number into the BC register pair.
| 06671 | JR C,E_L_1 | Jump forward if the number exceeds 65,536.
| 06673 | LD HL,55536 | Otherwise test it against 10,000.
| 06676 | ADD HL,BC
E_L_1 | 06677 | JP C,REPORT_C | Give report C if over 9,999.
| 06680 | JP SET_STK | Return via SET_STK that restores the calculator stack to its rightful place.