In Melanie's excellent write up she describes pre-setting TMR1 to $D8F0 and then allowing 20uS headroom, so adjusting TMR1 to $D910. Because the timer can be calibrated (by 100 uS) I guess this exact amount is not critical but just to make sure I understand (or not!), isn't this a 20 HEX difference or 32uS? What am I missing or not understanding?
Thanks

Adrian