newbie question

[mister_e]

Can i know what is the meaning of Poke command?

Poke is a PBC statement (still usable in PBP) who write to a specific register.

POKE PORTB, 10

will write 10 to PORTB

In PBP, you may reduce it to
PORTB=0
add a semicolon at the end of the line and it's in C

// is the modulus.

PBP performs 16x16 division. The '/' operator returns the 16-bit result. The '//' operator returns the remainder. This is sometimes referred to as the modulus of the number.

Example

W1 = W0 / 1000 ‘ Divide value in W0 by 1000 and place the result in W1
W2 = W0 // 1000 ‘ Divide value in W0 by 1000 and place the remainder in W2