Approprite baud

[mister_e]

There's no real such thing as Best Baudrate, but you need to consider the limitation of a software based Serial communication against Hardware.

If it was me, I would never have use Grandpa 16F84, let him alone on the shelf, he's retired anyways why Microchip still produce them anyways ... apart for money income & 100% compatible effortless drop-in replacement???

However, in case you MUST deal with it for some museum (or available parts) reason, I would suggest you to forget SEROUT but use DEBUG instead. Compare both, DEBUG will work on higher speed than SEROUT on slow speed crystal such as 4 MHz.

Using a built-in USART allow you to have at least interrupt... Way to go in most case as your software can do intelligent stuff in meantime.. what's the big deal to sit there and wait for something anyways

If you look at the PIC datasheet (or use my PICmultiCalc), you'll discover that your PIC running @4MHz may provide a still efficient 250K baud... BUT this will not work in your case, using 19,200 (see the comma Darrel?) baud and still be efficient on both part... considering you're using USART interrupt on the receiver end.