The ST-506 and ST-412 (sometimes written ST506 and ST412) were early hard disk drive products introduced by Seagate in 1980 and 1981 respectively, that
Mirror" Max Thieriot Kenny Ryan & Jacob Roman April 21, 2021 (2021-04-21) ST412 3.52 77 13 "Do No Harm" Tyler Grey Tom Mularz & Kinan Copen May 5, 2021 (2021-05-05)
used, but this was managed by the SCSI controller. It interfaced to a ST506/ST412-based Winchester unit via the BBC Micro's 1 MHz Bus, an Acorn-designed