brian@contex.UUCP (Brian Love) (01/22/91)
I am having trouble connecting a CDC Wren IV (344Mb SCSI) hard disk to my
A2000HD (see below for full system configuration). The documentation for
the Wren indicates very clearly the drive has 1549 cylinders, and (fairly
clearly) 9 data heads. The docs are not clear on BlocksPerTrack; by some
simple arithmetic, the drive must be able to support at least 50 512-byte
blocks per track. Of course, that configuration doesn't work.
When connecting a Vertex (80Mb ST-506) drive, I discovered that the prep
program does not like initializing disks with more than 7 or 8 surfaces
(the Vertex drive has 10). I found I could get around this by telling prep
the disk has only 7 surfaces, but telling mount the real number of
surfaces. To accomodate for this, I also have to lie to prep and tell it
the disk has more cylinders than it really has. For the Wren,
1549cyls/50bpt/9surf would map approximately to 1991cyls/50bpt/7surf. Of
course, that solution doesn't completely work either.
I've been able to get 4 partitions to work, using approximately 240Mb of
the disk. The 5th partition invariably fails. I don't trust all 1549
cylinders after the prep nonsense, so I create 1 partition from cyl 4 thru
cyl 1549 (or higher). The format of this partition always fails on
cylinder 1402. So I say, fine, I'll run my partitions up to cylinder 1400
and that'll give me 307Mb. And, of course, that doesn't work either. The
fifth partition will format all cylinders up to 1400, but I get a requester
saying "Not a DOS disk - Unit 6".
The problem does not appear to be related to the number of partitions. It
will format a single partition from cyl 4 thru 1400, but when it's done (2
and 1/2 hours later) I'm still left with "Not a DOS disk..." I do have a
SCSI 1/4" streaming tape drive on the SCSI bus (everything properly
terminated, I believe). I have not gotten the tape drive to work at all,
yet, however, it does not appear to be a factor in the Wren drive problem.
It has it's own SCSI id address and has never come to life during any of my
iterations. I heard a rumor that the SCSI driver "prefers" 17 blocks per
track. I suppose this can be handled in the same way as the Surfaces
discrepancy. I'll try this tonight.
I'm exceedingly frustrated. I'm strongly tempted to complain about the
lack of robust-ness in Amiga and amiga-related products, but I'll refrain
until (hopefully) some kind soul helps me and I know more about the
problem. I've reproduced the mountlist file below. I've removed all
unchanged keyfields from successive entries (Unit,Flags,Buffers, etc) to
save space.
mount.wren:
/* MountList entries for CDC Wren IV (344 MB SCSI) Hard Disk */
RES5: Device = hddisk.device
Unit = 6
Flags = 0
Surfaces = 7
BlocksPerTrack = 50
Reserved = 2
LowCyl = 0 ; HighCyl = 1
Buffers = 50
BufMemType = 5
/*
This entry is present only as a reminder ... it is commented out.
DH5: LowCyl = 2 ; HighCyl = 2
BufMemType = 0
*/
WR1: Surfaces = 9
FileSystem = l:FastFileSystem
LowCyl = 3 ; HighCyl = 352
GlobVec = -1
Mount = 1
DosType=0x444F5301
WR2: LowCyl = 353 ; HighCyl = 702
WR3: LowCyl = 703 ; HighCyl = 952
WR4: LowCyl = 953 ; HighCyl = 1202
WR5: LowCyl = 1203 ; HighCyl = 1400
system configuration:
A2000HD rev6 motherboard w/1.3 roms, 1M of chip ram, 8M of fast ram
(8-up!), 1 internal floppy drive, 1 external floppy drive, A2090A disk
controller with Rodime 40M ST-506 (internal), Vertex 80M ST-506 (external),
a belated Viper SCSI 1/4" streaming tape drive (internal), and a belated
Wren IV 344M SCSI disk (external).
For e-mail responses, please respond to an address below. The return-path my
mailer uses is broken.
Brian C. Love
E-mail: contex!brian@uunet.uu.net OR bcl@andrew.cmu.edu
Phone : (617) 224-5578 @work OR (617) 395-4476 @home