The 1551 is the weird outlier in the family of Commodore disk drives: It is the only drive using the “TCBM” bus instead of Serial or IEEE-488. And what’s even weirder? 1541 and 1570 drives converted into 1551s! The first Commodore disk drives for the PET were using the industry-standard parallel IEEE-488 bus. For cost … Continue reading Converting a Commodore 1541 or 1570 Drive into a 1551