connect two pics

[Jumper]

You say you have 2 pics, one small and one big and then you use the same code in both. In the small pic everything is dandy but with the 877A it is not working properly.

the code.... I agree.. what can go wrong... so the answer is probably not in the lines you posted.

What FQ do your run the pics on, and where do you get this one from?
Maybe DEFINE OSC XX in the beginning could help ....

Configurations bits... a long story.. and the bigger the pic.... the longer the story.. the best way to set configuration bits is by adding them to the code. How this is done depends if you use MPASM or not. Search the forum and add these bits into the top of your program... These have a significant effect on the pics behaviour.

OSC XT HS RC LP
Watchdog on off
Brown out or not
etc etc.. add all config bits you have for the device in the code

all these you can find in the datasheet....


And you still didnt answer how you power the pic and if you have caps close to the power pins.



/me