4 Jun
1998
4 Jun
'98
3:19 a.m.
OK, but what to do with the system that takes an
ST-506 interface drive? I just
need to know if I can substitute, say, an ST-251, and how to do the low-level
format (if necessary).
If it's a later (post-1985) ST-506 controller, you probably can use an ST-251
or larger drive. I've got some stuff that's from c. 1981 that assumes a
real ST-506 or TM603 or equivalent, down to the write precomp and reduced
write current. You can't use a newer drive (newer meaning ST-225 and up).
As a result, I've got a box of ST506 and ST412 drives (DEC RD-50 and RD-51),
and a couple of 5Mb Tandon mechanisms for the Commodore D9060 and D9090
IEEE-488 hard disks. I'd love to get a disassembly of the ROMs of thos
rives... They have a "DOS Board" (IEEE-488 to SASI) and a "Controller
Board"
(SASI to ST-506 interface). The drive parameters are in the ROMs of the
DOS board. There is a jumper to select 4 heads vs. 6 heads (5Mb and 7.5Mb).
Fun drive.
-ethan