I would strongly recommend you change this
#include <p16F628A.inc> ; processor specific variable definitions
__CONFIG _CP_OFF & _DATA_CP_OFF & _LVP_ON & _BOREN_ON & _MCLRE_ON & _WDT_ON & _PWRTE_OFF & _INTOSC_OSC_NOCLKOUT
then you can see what you are doing.
Then, I would change the _WDT_ON setting to _WDT_OFF as your problem is that the Watchdog Timer is triggering.
At the same time, I would change _LVP_ON to _LVP_OFF so you can use RB4/PGM as a GPIO pin,
and change _PWRTE_OFF to _PWRTE_ON to be sure power is stable before your code starts running.
Also note, once you #include p16F628A.inc, you won't need these lines any more.
TRISIO equ 0x85
GPIO equ 0x05
STATUS equ 0x03
OPTIONREG equ 0x81
INTCON equ 0x0b
TMR0 equ 0x01