[net.micro.att] ARC Disk Controller Card

josephs@ttidca.UUCP (Bill Josephs) (06/19/86)

	Does anyone have any experience, thoughts or ideas about the ARC
disk controller card is advertised in on page 173 of the June 17th 
issue of PC-Week?  The blurb says that it supports a 1-1 interleave 
factor vs. 1-6 for the standard XT disk.  Does it use onboard 
memory to "buffer" a full track of disk data?  Does one need to
reformat a disk if the ARC card is used to replace another controller?
What about fragmented disks files -- doesn't this defeat the speed
advantage?

	Thanks in advance...

						Bill Josephs
						Citicorp/TTI
						3100 Ocean Park Blvd.
						Santa Monica, Ca.

jeffm@mmintl.UUCP (Jeffrey Miller) (06/26/86)

In article <322@ttidca.UUCP> josephs@ttidca.UUCP writes:
>
>	Does anyone have any experience, thoughts or ideas about the ARC
>disk controller card is advertised in on page 173 of the June 17th 
>issue of PC-Week?  The blurb says that it supports a 1-1 interleave 
>factor vs. 1-6 for the standard XT disk.  Does it use onboard 
>memory to "buffer" a full track of disk data?  Does one need to
>reformat a disk if the ARC card is used to replace another controller?
>What about fragmented disks files -- doesn't this defeat the speed
>advantage?
------
Besides my 6300 I have a Televideo TeleCAT-286.  It's controller does
double buffering and reads a track at a time, so the interleave factor
is 1.  Although the drive is a Microscience 3425 (20M, 85ms avg. access),
disk access is EXTRAORDINARILY fast, even compared to a 40 ms AT drive.
If my drive were totally fragmented, that is, each file were split up into
individual sectors on different places around the disk, then my drive would
simply be the same speed as another with a different interleave factor in the
same condition.  This is virtually never the case, and several disk utilities
on the market can unfragment drives.
I unfortunately don't know the ARC controller, but I highly doubt TV makes
their own.  Perhaps it's the same one.  There must be more than one that
works this way by now.
You change the interleave factor WHEN and only when you do a low level disk
format.  You need to write info saying where the next logical sector is.


*

        *************************************************
        *       Jeff Miller                             *
        *       Multimate International Corp.           *
        *       52 Oakland Avenue                       *
        *       East Hartford, CT  06108-9911           *
        *       (203) 522-2116 x257                     *
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jeffm@mmintl.UUCP (Jeffrey Miller) (06/27/86)

In article <1604@mmintl.UUCP> jeffm@mmintl.UUCP (Jeffrey Miller) writes:
>------
>Besides my 6300 I have a Televideo TeleCAT-286.  Its controller does
>double buffering and reads a track at a time, so the interleave factor
>is 1.  Although the drive is a Microscience 3425 (20M, 85ms avg. access),
>disk access is EXTRAORDINARILY fast, even compared to a 40 ms AT drive.

I don't have a Microscience, it's a Miniscribe 3425.  Sorry for the booboo.

*

        *************************************************
        *       Jeff Miller                             *
        *       Multimate International Corp.           *
        *       52 Oakland Avenue                       *
        *       East Hartford, CT  06108-9911           *
        *       (203) 522-2116 x257                     *
        *  UUCP:                                        *
        * ...!seismo!utah-cs!utah-gr!pwa-b!mmintl!jeffm *
        *                                               *
 -->    * P.S. I can't *mail* to ARPA but I can receive *    <--
 -->    * from there.  News I *post* should get there.  *    <--
        *************************************************
*