Direct printing of 'bit' portion of byte fails if referenced by variable

[c-conversion]

I was struggling with a print statement in a program recently which wasn't working as I expected. I kept thinking I had my logic mixed up but eventually it turned out to be an oddity in the 'Print' statement.

It may be 'expected' behaviour, if 'unexpected' for me.

This works:

Print MyByte.0

Let MyByteBit = 0
Let MyReferencedBit = MyByte.MyByteBit
Print MyReferencedBit

This does not work reliably:

Print MyByte.MyByteBit

It will print "1" only if the most significant bit of MyByte is set to 1.
So if MyByte has a value > 127: Although this changed when I added an extra line to print spaces to the right of the decimal printed value? See the example program I used to test this.

Let MyByte = 128
Let MyByteBit = 0
Print MyByte.MyByteBit 'Prints 1
Let MyByteBit = 1
Print MyByte.MyByteBit 'Prints 1
...
Let MyByteBit = 7
Print MyByte.MyByteBit 'Prints 1

Let MyByte = 127
Let MyByteBit = 0
Print MyByte.MyByteBit 'Prints 0
Let MyByteBit = 1
Print MyByte.MyByteBit 'Prints 0
...
Let MyByteBit = 7
Print MyByte.MyByteBit 'Prints 0

Test program used:

#Chip 18F16Q41, 64

#Option Explicit
#Config CP=On

'LCD connection settings
#Define LCD_IO 4
#Define LCD_SPEED FAST
#Define LCD_NO_RW

'Port assignments
#Define LCD_RS        PortA.0
#Define LCD_Enable    PortA.1

#Define LCD_DB4       PortA.2
#Define LCD_DB5       PortC.0
#Define LCD_DB6       PortC.1
#Define LCD_DB7       PortC.2

Dim MyByte        As Byte
Dim MyByteBit     As Byte
Dim ReferencedBit As Bit
CLS

Let MyByte = 0

Do

    Locate 0, 0
    Print MyByte.7 'These print as expected
    Print MyByte.6
    Print MyByte.5
    Print MyByte.4
    Print MyByte.3
    Print MyByte.2
    Print MyByte.1
    Print MyByte.0

    Locate 0, 13
    Print MyByte
    'Print "  "
    'With the above line commented out, prints "1" when MSB set
    'With the line used, prints "1" when LSB set?

    Locate 1,0

    Let MyByteBit = 7
    Repeat 8
        Print MyByte.MyByteBit 'This does not print as expected.
        Let MyByteBit = MyByteBit - 1
    End Repeat

    Let MyByteBit = 7

    Repeat 8
        Let ReferencedBit = MyByte.MyByteBit
        Print ReferencedBit    'This prints as expected
        Let MyByteBit = MyByteBit - 1
    End Repeat

    Let MyByte = MyByte + 1

    If MyByte < 1 Then
        Let MyByte = 1
    End If
    Wait 100 mS

Loop

Now I am aware of this, I'm using this in my program:

If MyByte.MyByteBit = 1 Then
    Print "1"
Else
    Print "0"
End If

Which is 100% reliable.
At one point "Print MyByte.MyByteBit" printed nothing, not a "1", not a "0", nothing, as though the line was not even present. It was this behaviour that had me most confused.

As I said, it may be that I was trying to do something that isn't possible and that is what actually should happen. I only report it as it gave me half a day of head scratching and confusion.

[Anobium]

Great insights.

Print MyByte.MyByteBit is working as expected. And your logic is a good approach.