50pin 'Centronics' was very popular for SCSI, but there were a whole zoo of different connectors used. At the time SCSI was common, I was working in a data centre. We had a large cardboard box full of assorted SCSI cables. Sometimes even the one that was wanted.
Yes, some use 25pin D-sub connectors, some used mini two row 50pin or 3 row bigger size, apple had a square connector for their laptops and later external scsi used VHDCI connectors. Then there were a few different types of internal connector as well, with the later ones supplying power as well.
Used a lot on samplers as it was pretty much the only external connection standard suitable for HDD's, AKAI used SCSI even up to their last rackmount sampler, although that could also house an internal IDE drive and the previous model, the S5000/S6000, was originally designed to support IDE at somepoint but it was never implemented in the firmware.