RDTIM
Read system clock
| Function | Address | Description |
|---|---|---|
| RDTIM | FFDE | Read system clock |
This routine is used to read the system clock. The clock's resolution is a 60th of a second. Three bytes are returned by the routine. The accumulator contains the most significant byte, the X index register contains the next most significant byte, and the Y index register contains the least significant byte.
Example:
readClockRead the system clock and store in zero page
JSRRDTIM
STYFREKZPLeast significant byte
STXFREKZP+1
STAFREKZP+2Most significant byte
RTS
Note: FREKZP (0x00FB) in this example is a 4 byte block of zeropage memory unused by Basic or Kernal and is available for user code.
Last modified October 19, 2021: Remove weighting so left index is now alphabetical (cbe7734)