Path: utzoo!mnetor!uunet!ncc!alberta!att-ih!gargoyle!ddsw1!karl
From: karl@ddsw1.UUCP (Karl Denninger)
Newsgroups: comp.unix.microport
Subject: Re: Misc uport bugs and observations
Message-ID: <946@ddsw1.UUCP>
Date: 8 Apr 88 17:33:37 GMT
References: <4387@b-tech.UUCP> <1446@bigtex.uucp> <924@ddsw1.UUCP> <1469@bigtex.uucp>
Reply-To: karl@ddsw1.UUCP (Karl Denninger)
Organization: Macro Computer Solutions, Inc., Mundelein, IL
Lines: 57
Summary: It's easy to tell..

In article <1469@bigtex.uucp> james@bigtex.UUCP (James Van Artsdalen) writes:
>IN article <924@ddsw1.UUCP>, karl@ddsw1.UUCP (Karl Denninger) wrote:
>> [...]  You can't prep the
>> disk low-level under DOS if you're going to use it with UNIX; seems as
>> though you *MUST* low-level format to get the bad-track table on there
>> (so says their tech support...  why?).  In any event, the formatter goes 
>> ahead and uses 2:1 interleave, with NO CHOICE! AARRGGHHH!!!!  Only 
>> 240K/second transfer rate results, 1/2 what the system is capable of.
>
>For the record: I low-level format my disks with Western Digital's programs,
>not with uPort's.  This can be inconvenient.  To accomplish this, you must
>modify the INSTALL script on a copy of the build disk.  Change the interleave
>to the correct value.  If you don't, the bad block table is created with the
>wrong values and your system is about to hang...
>
>Karl, are you sure it formatted at 2:1 interleave?  The INSTALL script on my
>disks assumes 1:1 for Televideo and 3:1 for all others.  I don't know of any
>way to determine the actual interleave after formatting.

Actually it's quite trivial; run CORETEST, which measures the transfer rate,
and compute from there.  It's given reliable numbers for us so far; with a
2:1 interleave (the Uport/386 drive) you see about 240k/second through the 
drive system, the OTHER drive which was formatted with DOS reports the 
(correct) 490K/second transfer rate.

Your comment above about the "wrong" bad track entries is interesting, and
may lead to the FINAL reason for this discrepancy.... When I tried to
install on a HD prepped from Speedstor (my favorite) at 1:1, installation
began ok, then blew up with what was an obvious R/W error on the drive.
Now, I DID specify where the bad spots were during installation; is it 
possible that Uport has blown it w/regards to the mapping of bad regions 
on the disk (ie: BFI <> sector number translation) and is using 2:1
tables for the Televideo?  If this is the case, then 1:1 using their
installation script is not achievable (although cheating might do it).

>If all else fails, it is possible to manually build the /etc/partitions file
>on the build disk and then use "mkpart -i disk0" to initialize the VTOC.  This
>is a pain, but can be done.  For my own use I now have a modified INSTALL
>script that uses the /etc/partitions file on the build disk, and have put "ed"
>on the build disk so I can edit the partitions file on floppy.

Does this ALSO take care of badtracking correctly?  Technical support at
implied that it had something to do with the formatting process (which
doesn't seem right; I've looked at that partitions file).

Can I then assume that if the file '/etc/partitions' is created on the
floppy I can use 'mkpart -i disk0' to init a low-level formatted HD with the
info in that file?  This actually works?

I take it you need to hand-code the defect locations for this as well...

This is a major mess, Microport!

-----
Karl Denninger                 |  Data: +1 312 566-8912
Macro Computer Solutions, Inc. | Voice: +1 312 566-8910
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