Here's some raw data on DEC hard drives... This will need to be more html-ized in the near future. Also more data is needed :)
Drive Size FormFactor Height Interface ----- ---- ---------- ------ --------- RZ23 104MB 3.5" 1" SCSI1 CCS RZ26 1GB 3.5" 1" Fast SCSI2 RZ55 320MB 5.25" FH SCSI1 CCS RZ56 640MB 5.25" FH SCSI1 CCS RZ58 1380MB 5.25" cyl=2114 acyl=2 pcyl=2112 head=15 nsect=85 rpm=5400 bpt=44823 fmt_time=4