bit_byte1 var byte
bit0 var bit_byte1.0
bit1 var bit_byte1.1
bit2 var bit_byte1.2
bit3 var bit_byte1.3
bit4 var bit_byte1.4
bit5 var bit_byte1.5
bit6 var bit_byte1.6
bit7 var bit_byte1.7

uses 1 byte

mybit var Bit

uses 1 byte

mybit0 var Bit
mybit1 var Bit

I think uses 2 bytes .

you can verify this by checking your ????.lst file after compiling ????.pbp