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