This is a very simple and well-known mod for the Macintosh Plus, but I haven't seen it documented on TD so here goes:
The Plus does not provide termination power on the SCSI interface from the factory, but has the requisite circuitry to do so, if you add a diode to CR1 on the logic board (right behind the SCSI DB25 connector.)
An appropriate diode to use is 1N4001 50V/1amp, or any other 1amp diode with similar voltage rating. The one I'm using in the picture here is a 200V/1amp part salvaged from a discarded Apple IIGS PSU board.
The Plus does not provide termination power on the SCSI interface from the factory, but has the requisite circuitry to do so, if you add a diode to CR1 on the logic board (right behind the SCSI DB25 connector.)
An appropriate diode to use is 1N4001 50V/1amp, or any other 1amp diode with similar voltage rating. The one I'm using in the picture here is a 200V/1amp part salvaged from a discarded Apple IIGS PSU board.
