If you just need to send data to 2 PCs, you need not bother with RS485. Just make sure you have the MAX232 on your PIC side to ensure that your RS232 level is within spec. Then take the output of the MAX232 and connect to the RXD pin of each PC. You may connect only 1 TXD pin of any one PC to your MAX232 to get commands to your PIC.

Effectively, what will happen is that whatever your PIC sends will be received by both PCs. What you type on the 1 pc whose TXD is connected to your PIC will be received by your PIC.