Jim, I sent you a mail directly to not increase the noise on the list, but I havent any answer from you. I have seen that you answer to the guy asking to the list. Now I ask to the list too, maybe I got the answer. I don't know if there are some tight timing loop that don't tollerate 1.3% clock error. LMK ciao Claudio Rachiele IW0DZG ---------------------- Forwarded by Claudio Rachiele IW0DZG/Italy/IBM on 10/20/99 10:54 AM --------------------------- Claudio Rachiele IW0DZG 10/18/99 10:45 AM To: newfound@pipeline.com.au@internet cc: From: Claudio Rachiele IW0DZG/Italy/IBM@IBMIT Subject: phoenix Jim, I bought your phoenix 17C42 to make a parallel programmer for 16C5x. The original schematic use a 5.068 MHz xtal. I can't found it in my country. Can I use a 5 MHz xtal istead of or the timing error ( 1.3 % ) is too great to let the programmer works ? TIA Claudio Rachiele IW0DZG