The BBC and Master Computer Public Domain Library
Next non-space Char PTRB
Submitted by Steve Fewell
Routine: NextCharPTRB
Name: Next non-space Char PTRB
Starting Address: &8ED5
Exit: Move past spaces in BASICs Text
Pointer B and return the next Character in the string. Y is the PTR B offset of the character
Description:
Reads past any space characters found at the current position in the PTRB.
Returns with the next non-space Character from PTRB in A, and with the PTRB
Offset pointing to this value.
Routine &8EEB returns the next non-space character in PTRB, and also sets
the zero flag is the character is a comma (','), or clears the zero flag is the
character is not a comma.
Disassembly for the Next non-space Char PTRB routine
| 8ED5 | 164 027 | A4 1B | LDY &1B | |
| 8ED7 | 230 027 | E6 1B | INC &1B | |
| 8ED9 | 177 025 | B1 19 | LDA (&19),Y | |
| 8EDB | 201 032 | C9 20 | CMP#&20 | |
| 8EDD | 240 246 | F0 F6 | BEQ -10 --> &8ED5 | |
| 8EDF | ` | 096 | 60 | RTS |
Get Next non-space Char PTRB and compare with ','
| 8EEB | 032 213 142 | 20 D5 8E | JSR &8ED5 | |
| 8EEE | , | 201 044 | C9 2C | CMP#&2C |
| 8EF0 | ` | 096 | 60 | RTS |
