A Hatfield man who admitted attacking his roommate with a kitchen knife has been given 11 1/2 to 23 months in Montgomery County Prison. 51-year-old Fidel Canales pleaded guilty to aggravated assault Wednesday in Montgomery County Court. He shared a Union Street apartment with the victim. Court documents say the roommate suffered cuts on his hands when he tried to defend himself. Canales became angry when the victim refused to drink alcohol with him. He is apparently in the country illegally, and he can be released only to federal immigration officials when he gets out of jail.