[comp.sys.ibm.pc] Do not order from PC-BRAND

m_belanger@mosaic.dec.com (07/21/89)

I purchased their 396/25 machines about 4 months ago and after the first
initial problems with (a) the system and (b) their support staff, I finally
managed to get the machine working.

Initially, I wasn't aware of the disk controller's internal configuration
setup utility which had to be run for disk setup.  Also, the ON-TRACK disk
configuration utility for low-level formatting had me confused.  Once I
understood how these things were done (the support staff was anything but
helpful) the system came up fine.  I have a Miniscribe 3180E hard disk,
which is not supported under DOS since it's greater than 1024 cylinders.

All in all the system has had no problems yet that would require a call to
their support staff (and I hope I never have to) and it runs quite well for
what I ended up spending for.

Moe Belanger

keithe@tekgvs.LABS.TEK.COM (Keith Ericson) (07/21/89)

In article <459@mountn.dec.com> m_belanger@mosaic.dec.com writes:
>I have a Miniscribe 3180E hard disk,
>which is not supported under DOS since it's greater than 1024 cylinders.

With a properly-designed interface card the >1024 cylinders
restriction is circumvented by re-mapping the 17, 26 or 34 "real"
sectors per track to 52, 54 or 63 "logical" sectors per track. 
Also, the "real" head count can be translated to a "logical" 15 or
16.  Then you can do

           Formatted Capacity
       ----------------------------
	512 x [15|16] x [52|54|63]

to get a "logical" cylinder count of < 1024.

Playing these tricks with maximum values permits a maximum
per-drive capacity of approximately 528 Megabytes.

kEITHe

wcf@psuhcx.psu.edu (Bill Fenner) (07/24/89)

In article <5621@tekgvs.LABS.TEK.COM> keithe@tekgvs.LABS.TEK.COM (Keith Ericson) writes:
|In article <459@mountn.dec.com> m_belanger@mosaic.dec.com writes:
|>I have a Miniscribe 3180E hard disk,
|>which is not supported under DOS since it's greater than 1024 cylinders.
|
|With a properly-designed interface card the >1024 cylinders
|restriction is circumvented by re-mapping the 17, 26 or 34 "real"
|sectors per track to 52, 54 or 63 "logical" sectors per track. 

OnTrack Technology's Miniscribe Disk Manager, v3.6, has a little BIOS extender
program that patches your BIOS to allow more than 1024 cylinders.  I installed
a 3180 in a 386 with an ESDI controller, using Disk Manager, and it works
very well.  I can't say much for the amount of RAM it takes up, but... ya
gotta take the good with the bad, I suppose. :-)

  Bill

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