ewing@se-sd.NCR.COM (David Ewing ) (09/12/89)
I have some questions about setting up my Quantum 40s hard disk
with the Microbotics HardFrame using the HardFrame's RDPrep
program.
I want to have two partitions, but all of the defaults in RDPrep
assume you are only going to have one partition. I decided to
make my partition at the point where the sectors/track density
changes, as recommended.
--> Cylinders 0 to 589 contain 35 sectors per track, 105
physical sectors available.
--> Cylinders 590 to 833 contain 26 sectors per track, 84
physical sectors available.
My questions are:
Do you need to (can you) set up a Rigid Disk Block for each partition ?
If no, how does the controller know that the second partition
has a different number of sectors/track ?
Apparently, the recommended default for the Quantum is 32 sectors
per track. Is this just a compromise between the two values
(35 and 26) ?
What is "logical blocks per track" (asked for each partition) and
why is the default 98 ?
I assume it is desirable to set up both partitions with the Fast
File System. Is this correct ?
What exactly do I need to add to Startup-Sequence (I am booting
from the hard disk). It says SETPATH must be the first command.
What is the exact command in its entirety ?
Could some kind person send me answers to these questions and any other
pertinent information that I might need to know.
Note: I have a stock Amiga 2000 (1 megabyte of RAM).
Thanks in advance,
Dave Ewing
ewing@se-sd.sandiego.ncr.comtj@shawnee.cis.ohio-state.edu (Todd R. Johnson) (09/12/89)
In article <2038@se-sd.NCR.COM> ewing@se-sd.sandiego.ncr.com (David Ewing (AEP)) writes:
< I have some questions about setting up my Quantum 40s hard disk
< with the Microbotics HardFrame using the HardFrame's RDPrep
< program.
<
With the MB documentation (or lack) its no wonder you have questions.
< I want to have two partitions, but all of the defaults in RDPrep
< assume you are only going to have one partition. I decided to
< make my partition at the point where the sectors/track density
< changes, as recommended.
<
If you are on BIX, you can download a beta RDPrep that is
supposed to be better than the old version.
< --> Cylinders 0 to 589 contain 35 sectors per track, 105
< physical sectors available.
<
< --> Cylinders 590 to 833 contain 26 sectors per track, 84
< physical sectors available.
<
This will not work for several reasons. First, MB is wrong
about the number of sectors per track from 590 - 833. It is actually
28, not 26. 3 heads * 26 sectors/track = 78 sectors per cylinder.
However, you actually have 3 heads * 28 sec/track = 84 sec/cyl.
Second, 590 * 105 + 244 * 84 = 82,446 total sectors. However,
one sector for every 6 tracks is used for default management, so you
can't use all 82,446 sectors for data. 82,446 - 417 (for default
management) leaves 82,029 usable sectors.
Third, your mountlist entries can't use all of these sectors
because the first part of the drive must be set up as the Rigid Disk
Block. Usually the first cylinder is used for this.
Fourth, if you set up two mountlist entries with the second
having a smaller number of sectors per track than the first, you will
actually end up with overlapping partitions. This occurs because each
entry is used to compute a sector number without respect to other
entries. AmigaDos then uses this sector number to access the disk.
If you were to create the mountlist entries you suggest above, the
first partition would end at sector number 590*105 - 1 = 61,949, but
the second partition would start at sector number 590*84 = 49,560 and
end at 834*84 - 1 = 70,056. Because the second Mountlist entry has 28
sectors per track, AmigaDos assumes that the first 590 sectors also
have 28 sectors per track when it calculates sector numbers for the
second partition.
To overcome this you need to calculate the logical number of
cylinders, heads, and sectors per track that will result in the total
number of usable sectors. Then you use these numbers to make your
mountlist entries. It doesn't matter if the numbers don't actually
correspond to the physical construction of your drive, because they
are only going to be used by AmigaDos to compute sector numbers.
For a 40S use these numbers:
737 cylinders, 3 heads (surfaces), 37 sectors per track
737*3*37 = 82,029 the total number of usable sectors.
If you these numbers to set up your two entries (remembering that the
first cylinder will be used for the RDB), you will be able to describe
the partitions as if they have identical numbers of sectors per track.
Thus, AmigaDos will correctly compute sector numbers that don't
overlap. Note, that you don't have to worry about actually making the
partitions where the density changes. AmigaDos doesn't care what the
disk actually looks like, it just needs to be able to compute sector
numbers that don't overlap.
< My questions are:
<
< Do you need to (can you) set up a Rigid Disk Block for each partition ?
Just one for the entire disk.
< If no, how does the controller know that the second partition
< has a different number of sectors/track ?
It doesn't.
< Apparently, the recommended default for the Quantum is 32 sectors
< per track. Is this just a compromise between the two values
< (35 and 26) ?
Yes, and not a very good one. 32*3*844 = 81,024 sectors. You
lose 1005 sectors. I beleive that the beta RDPrep will actually
compute numbers similar to the ones I've suggested above.
< What is "logical blocks per track" (asked for each partition) and
< why is the default 98 ?
Not sure about this one.
< I assume it is desirable to set up both partitions with the Fast
< File System. Is this correct ?
Unless you crave a slow HD. With 1.3 roms and the HF you
don't need to use an OFS partition.
< What exactly do I need to add to Startup-Sequence (I am booting
< from the hard disk). It says SETPATH must be the first command.
< What is the exact command in its entirety ?
Setpath or setpatch? All I did was change various floppy
assigns to put to HD directories.
< Could some kind person send me answers to these questions and any other
< pertinent information that I might need to know.
<
< Note: I have a stock Amiga 2000 (1 megabyte of RAM).
<
< Thanks in advance,
<
< Dave Ewing
< ewing@se-sd.sandiego.ncr.com
---Todd
-=-
---Todd
tj@cis.ohio-state.edujdm@gryphon.COM (John Mesiavech) (09/14/89)
In article <2038@se-sd.NCR.COM> ewing@se-sd.sandiego.ncr.com (David Ewing (AEP)) writes: >I have some questions about setting up my Quantum 40s hard disk >with the Microbotics HardFrame using the HardFrame's RDPrep >program. > Well, I didn't design the thing, but I own one and have a Pro40S....... > >I want to have two partitions, but all of the defaults in RDPrep >assume you are only going to have one partition. I decided to >make my partition at the point where the sectors/track density >changes, as recommended. > Now, this is where you made your first mistake. SCSI deals in sector numbers, NOT in the drive's physical geometry. This is an common mistake, that RDPrep suffers from as well. What you must do, in order to fully utilize the drive's sectors is: Calculate the TOTAL number of blocks on the drive. To do so, take the numer of BlocksPerTrack and multiply by the number of Cylinders in each zone (a zone is each area of the drive that has unique settings for BlocksPerTrack values), then add the numbers together. That gives you total number of Blocks, then geometize them as you want. What RDPrep does internally is get the zone values, then divide the total Blocks by the number of Cylinders on the drive to get an average BlocksPerTrack value. Problem is, this rarely comes out even (ie remainder of 0 blocks), which is what you want. RDPrep warns you about that, by saying that you'll have X number of blocks left over is you follow the defaults. It just takes a leetle fiddling to get it to come out even. Default parameters for a Pro 40S Quantum leave 287 blocks out. > --> Cylinders 0 to 589 contain 35 sectors per track, 105 > physical sectors available. > > --> Cylinders 590 to 833 contain 26 sectors per track, 84 > physical sectors available. > >My questions are: > > Do you need to (can you) set up a Rigid Disk Block for each partition ? No. You can only have one Rigid Disk Block area per drive. That's why the necessity of geometizing (redefining the geometry until you get an exact match) is needed. This is true of ALL controllers. It's not really necessary (since the geometry is NOT fixed) to have more than one. > > If no, how does the controller know that the second partition > has a different number of sectors/track ? The controller doesn't CARE how the drive is laid out internally. Those functions are left up to the onboard drive controller (the circuit card attached to the bottom of the drive). All that the Hardframe has to worry abou is the TOTAL number of blocks on the drive, which it determines at startup from the Rigid Disk Block information stored on the drive. All that's actually stored IN the RigidDiskBlock is the total number of blocks, and how many are allocated to each partition, and where the starting block of each partition is. > > Apparently, the recommended default for the Quantum is 32 sectors > per track. Is this just a compromise between the two values > (35 and 26) ? See above in me reply. It's an average value. > > What is "logical blocks per track" (asked for each partition) and > why is the default 98 ? THat's used to set up the drive partitions in a way AmigaDOS understands. You see, the Hardframe tells AmigaDOS that each drive only has 1 head, with whatever number of BlocksPerTrack it takes to make up the ACTUAL BlocksPerTrack value. Since the Quantum has 3 heads, it follows. It's for AmigaDOS use only, the controller knows the real values. That's why it's called LOGICAL. > > I assume it is desirable to set up both partitions with the Fast > File System. Is this correct ? Well, if you want to get the most speed that AmigaDOS can handle outta that drive, yes. Matter of fact, you really have no choice in the matter. RDPrep requires a disk file to read, to get the filesystem information for the drive. Since OldFS can only be gotten in the ROMsm , you can't use it with the HardFrame. Though, if you wanted to be strange, you could get CrossDos and put their MSDosFileSystem handler onto a partition, and have an IBM drive B-> > > What exactly do I need to add to Startup-Sequence (I am booting > from the hard disk). It says SETPATH must be the first command. > What is the exact command in its entirety ? THe command is SetPatch, and in the C-A Workbench 1.3 it IS the first command. Exact command is: SETPATCH Or, if you don't want to see what SetPatch is patching, the command is: SETPATCH >NIL: Easy, isn't it? > >Could some kind person send me answers to these questions and any other >pertinent information that I might need to know. > Sho 'nuff, tho I can't say what you might NEED to know without knowing all you already do........8-> >Note: I have a stock Amiga 2000 (1 megabyte of RAM). So, what difference does this make? Me Amiga has a 2620, Hardframe with Quantum Pro-40S, Quantum Q280,and a Syquest SQ550 44MB removable media drive(Gotten at a rediculous price NEW) ,Easyl-2000 graphics tablet, and Microbotics 8-up SIMM w/4MB. It matters not what KIND of Amiga you have, but that you have an Amiga! > >Thanks in advance, > >Dave Ewing >ewing@se-sd.sandiego.ncr.com Again, no problemos, amigo. John
jwright@atanasoff.cs.iastate.edu (Jim Wright) (09/15/89)
In article <19859@gryphon.COM> jdm@gryphon.COM (John Mesiavech) writes: | Now, this is where you made your first mistake. SCSI deals in sector | numbers, NOT in the drive's physical geometry. [lots of good stuff...] I know that to the computer, the physical layout of a SCSI drive is hidden. But does AmigaDOS perform any optimizations based on (presumed) drive geometry? Like adjusting file placement to minimize head movement? What I'm getting at is, suppose I set one drive up as the "real" layout and set a second drive as one head, one track and a zillion blocks per track. Would they perform the same under AmigaDOS? -- Jim Wright jwright@atanasoff.cs.iastate.edu