When I try to compile the following code with MicroCode Studio 3.0.0.5 melabs Programmer 4.23 and PBP 2.50b

< OSCCAL = $58
GPIO = 0
CMCON = 7
ANSEL = 0

TRISIO = %00111000
OPTION_REG = %10000000


Pulse:
ASM
bsf gpio, 0
goto $+1
goto $+1
goto $+1
goto $+1
goto $+1
goto $+1
bcf gpio, 0
goto $+1
goto $+1
goto $+1
goto $+1
goto $+1
goto _Pulse
ENDASM

goto Pulse

end>

I get error[113] Symbol not previously defined (gpio)

What am I missing?

Thanks
Aaron