Path: utzoo!attcan!uunet!portal!cup.portal.com!BobR
From: BobR@cup.portal.com (Bob BobR Retelle)
Newsgroups: comp.sys.atari.8bit
Subject: Re: Was: Flight Sim II <=> XF551 incompatible forever
Message-ID: <10907@cup.portal.com>
Date: 5 Nov 88 06:58:55 GMT
References: <12907@eecae.UUCP> <4578@bsu-cs.UUCP> <31836@bbn.COM>
Organization: The Portal System (TM)
Lines: 51

Stan Lackey asks:
>I'm so confused.
 
>In article <4578@bsu-cs.UUCP> cptpower@bsu-cs.UUCP (Mike Wildridge) writes:
>>... As any
>>other XF551 owner knows - all the stuff on the 1050 is not compatible if you
>>notched and wrote on the back of your disk.  (The XF551 writes on the back
>>of the disk BACKWARDS - leave it to Atari to make unnecessary improvements.)
 
>I have seen references to this several times now.  Why does anybody care what
>the back of a 1050 disk looks like?  Is there a way on the 551 to access the
>back of a 1050-formatted disk without turning it over?  Under Atari DOS? 
>Please explain using no more than 2-syllable words.
>-Stan

Sigh...  I'm afraid I'd use up the entire Net bandwidth trying to explain
this...   I'll try to hit the "high" points, but for more "in-depth"
info about the *supposed* XF-551 incompatibilities, watch for an article
by Matt Ratcliff in an upcoming issue of (I think) ANALOG magazine.

First of all... THERE IS NO COMPATIBILITY PROBLEM..!

This is all a "semantics" problem, a massive misunderstanding of the way
disk drives work...
 
The XF-551 is a *standard* Double Sided disk drive.  It has a
read/write head on BOTH sides of the disk, so it can write to both sides.
 A "single sided" drive, like the 1050 has a head on only ONE side, and
it IS NOT supposed to write to the other side..!  Atari owners have found
ways to get around this by manually turning the disk over, and using the
other side as if it was a *second* SINGLE SIDED disk...  BUT...  these
"Flippy disks"  ARE NOT "true" Double Sided disks.
 
Actually, it is the *1050*  which "writes backwards" on the back side
of a disk, because it is writing the back as if it was the "front" of
another disk.  When you put a "flippy" in an XF-551, the back side has
been written in a *non-standard* way, and thus cannot be read, UNLESS you
manually turn it over, just like on a 1050...  in that case, it will read
just fine..!
 
It's awfully hard to explain without some kind of illustrations to go
along with the text...  but the bottom line is, there is NOTHING wrong
with the XF-551, it just can't read the back side of the NON-STANDARD
"Flippy" disks without turning them over manually.

If you've been "flipping" your disks, you'll still have to flip them in
an XF-551.  Any disks you write as "true" Double Sided disks with an 
XF-551 will not be able to be read by "flipping" them in a 1050...
these are not "bugs", it's just the way it works..!
 
BobR       (Can you believe it..?  I'm actually defending Atari! :)