I'm not using hte solderless breadboard for my test circuit. I have moved from the dt-001 programmer to a simple p16pro40 programmer. Now i get the first byte from the PIC (which is wrong), and the rest still shows as 3FFF. More details on the setup: The plug from programmer is a db9 (5 wires for the circuit, 4 for programming, both have a common GND), and i used single strand wire from the db9 to the veroboard. How to i minimise the amount of noise and capacitance on the clock and data line? Im pretty sure now that the MCLR line on the p16pro40 is rising fast enough. Daren From: "John J. McDonough" Reply-To: "John J. McDonough" To: "pic microcontroller discussion list" Subject: Re: [PIC:] VIHH on MCLR doesnt put PIC in programming mode Date: Wed, 7 Jan 2004 16:47:06 -0500 ----- Original Message ----- From: "Daren X" Sent: Monday, January 05, 2004 5:43 PM Subject: [PIC:] VIHH on MCLR doesnt put PIC in programming mode > The PIC is definitely running when MCLR is at 12v as the LCD displays > the intro message and rs232 communications begin. I think John Power made a very important point. !MCLR needs to go from 0 to 12 within a few microseconds without spending any significant time near 5 volts. He suggests 1 us. I'm not sure of that, but I know it needs to be less than 4 us. In moving from your programmer to the test circuit, there are 2 obvious possibilities; 1) If there is a capacitor on !MCLR, it can prevent you from getting up to 12 volts quickly and 2) if the lines from your test circuit are longer and/or have higher capacitance, they can have the same effect. 72/73 de WB8RCR http://www.qsl.net/wb8rcr didileydadidah QRP-L #1446 Code Warriors #35 _________________________________________________________________ E-mail just got a whole lot better. New ninemsn Premium. Click here http://ninemsn.com.au/premium/landing.asp -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads