Hi Harry, It controls pulsators for milking cows ... :) It has four outputs ... two lots of two. Each pair alternates at either 50, 60 or 90 times a minute ... and the ratio of on to off can be varied to either 30/70, 60/40, 65/35 or 70/30. This is set by links to four different inputs ... once the farmer decides on the settings, it left to run maybe for years at those settings. There is one input which is connected to a current monitoring circuit and if that goes high, the device stops pulsating until the power is turned off and it resets. As you can imagine, the timing is not super critical ... just needs to be reliable. I made a mistake in the original post ... while a replacement board may be $1200 .. a replacement system can be up to $2500 (not $1500). One of the guys chasing me to do this says that if I were to give him a bill for $500 to repair a board, he'd be very happy. Still seems worthwhile pursuing to me. Obviously I still have to write the program, but I have monitored a working one and have all the waveforms and timings. Compared to some of the programs I have written this is still a very simple ask .. it's the hardware questions I want to get right first. Thanks for all the input so far. Regards, Roger ----- Original Message ----- From: "Harry H. Arends" To: "'Microcontroller discussion list - Public.'" Sent: Thursday, 13 August, 2009 6:32 PM Subject: RE: [PIC] Advise on replacing an obsolete micro with a PIC > Maybe a question about the function. What does it do and what is the > program it runs? > > Harry >> -----Oorspronkelijk bericht----- >> Van: piclist-bounces@mit.edu [mailto:piclist-bounces@mit.edu] >> Namens Roger Weichert >> Verzonden: donderdag 13 augustus 2009 7:33 >> Aan: Microcontroller discussion list - Public. >> Onderwerp: Re: [PIC] Advise on replacing an obsolete micro with a > PIC >> >> Thanks Bob, >> >> The pinout of this one is ... >> >> 1: Crystal >> 2: Crystal >> 3: Output >> 4: Output >> 5: Output >> 6: Output >> 7: I suspect it's a Reset pin >> 8: Ground >> 9: Ground >> 10: Input ... maybe with Interrupt >> 11: Input >> 12: Input >> 13: ? Pulled High >> 14: Input >> 15: Input >> 16: Supply 5.6 Volts >> >> Regards, Roger >> -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist