| Title: | AMIGA NOTES |
| Notice: | Join us in the *NEW* conference - HYDRA::AMIGA_V2 |
| Moderator: | HYDRA::MOORE |
| Created: | Sat Apr 26 1986 |
| Last Modified: | Wed Feb 05 1992 |
| Last Successful Update: | Fri Jun 06 1997 |
| Number of topics: | 5378 |
| Total number of notes: | 38326 |
I bought a refurbished CDC 86Meg SCSI disk drive at the Computer Flea
market on Saturday. Great price, seems to power up fine, etc.
It responds to a SCSI Inquire command with:
UNIT 0 Present -> CDC 94216-5 Size = 91570688 Bytes
Using a CAP 0 command it says:
Capacity of ADDRESS 0 = 178849 Sectors, 91570688 Bytes
So it looks like works, but I'm paranoid about harddisks and
so would like to do a low level format of it. Do any of you
harddisk wizards have info on things like # of of heads, tracks,
sectors per track for that drive? The Cltd stuff I have only
lists a CDC 92171.
Many thanks in advance,
-Dave
| T.R | Title | User | Personal Name | Date | Lines |
|---|---|---|---|---|---|
| 3081.1 | Pick three numbers | TLE::RMEYERS | Randy Meyers | Tue Nov 07 1989 17:34 | 31 |
Re: .0 > So it looks like works, but I'm paranoid about harddisks and > so would like to do a low level format of it. Do any of you > harddisk wizards have info on things like # of of heads, tracks, > sectors per track for that drive? For a SCSI disk, it really doesn't matter(*). The only way to talk to the disk is in terms of sector numbers. Pick three numbers that multiply out to the number of sectors on the drive, and claim that is the number of heads, tracks, and blocks per track. For help picking three numbers that multiply out to the size of your drive, find the prime factors of the number of sectors. Since AmigaDOS more or less reserves cylinder zero, you probably should use a geometry that somewhere between 100 to 300 blocks per cylinder. (Cylinder zero is used to store the drive's partition info plus the file system for disk controllers that support FastFileSystem autoboot.) Some high end drives (those that use zoned recording) don't have a physical geometry that can not be expressed in terms of the number of heads, tracks, and blocks per track for the entire drive. All that matters is the logical geometry address all the blocks in the drive. * Well, if you were really clever, you could try to allocate files so that they appeared on a cylinder boundary, but AmigaDOS doesn't do this. AmigaDOS DOES allocate the root directory on the basis of the drive's geometry (or what you tell it is the drive's geometry), so once you do a high level format, you should leave the drive's geometry alone. | |||||
| 3081.2 | WJG::GUINEAU | Quantum Reality | Tue Nov 07 1989 19:45 | 9 | |
If you really want to know, (and it looks like you can issue SCSI commands) try a MODE_SENSE for page 3 and page 4. Page 3 bytes 10 and 11 are the MSB and LSB of the number of sectors Page 4 bytes 2 to 4 are MSB to LSB of the number of cylinders Page 4 byte 5 is the number of heads. john | |||||
| 3081.3 | BAGELS::BRANNON | Dave Brannon | Tue Nov 07 1989 21:42 | 5 | |
re: .1,.2
Thanks, will try it.
-Dave
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