Unofficial Name: DispHeader
BCALL Address: 512E
Minimum OS Version: 2.30
Displays zero-terminated string at OP3 in top-left corner and sets (winTop) to 1.
- OP3: zero-terminated string to display
This routine minds the split screen flag (setting (winTop) to 5 instead).
It also erases the rest of the first line after the string is displayed.