The Jargon File (version 4.4.7, 29 Dec 2003):
monkey up vt. To hack together hardware for a particular task, especially a one-shot job. Connotes an extremely crufty and consciously temporary solution. Compare hack up, kluge up, cruft together.The Free On-line Dictionary of Computing (30 December 2018):
monkey up To hack together hardware for a particular task, especially a one-shot job. Connotes an extremely crufty and consciously temporary solution. Compare hack up, kluge up.