If you are interested you can replace the confusing subroutine with a generic delay type routine that I always use. This one just uses the A register and one level of the stack. You call this with an entry A value to determine a total delay. As shown below I have setup the design for your crystal frequency. If you call this delay routine two times with an entry A of #150 you will acheive a total delay of close to 300 msec.


For those interested in looking more closely at the spreadsheet calculator it is in Excel format and can be fetched via the link below.
Get Spreadsheet Calculator

Have Fun
Mike Karas