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From: mfolivo@sactoh0.sac.ca.us (Mark Newton John)
Newsgroups: comp.sys.atari.8bit
Subject: DOS 3 and DOS 4
Keywords: The XL DOS (1450XLD)
Message-ID: <1991May3.072038.21653@sactoh0.sac.ca.us>
Date: 3 May 91 07:20:38 GMT
Organization: Sacramento Public Access Unix
Lines: 44


I want to correct one inaccuracy. The DOS that was designed for the
1450XLD was not DOS 4, but DOS 3.

I consider myself an expert, being about the last person in the
Western Hemisphere that used DOS 3 instead of SpartaDOS. (reasons
I'll not go into here...) Then I got an ST, but I digress.

The 1450XLD was a huge XL, with a double-sided (enhanced)double
density drive built in, with an expansion bay for a second drive.
It had a metal case, so you could put a monitor on top of it. If
this is sounding like an Apple III, you're not too far off. Both
were dogs, although a 1450XLD would command a far greater price
than any Apple III, if you can even FIND an XLD. But I digress
again.

DOS 3 was a wierd one alright, but in trying to remain compatible
with all the single sided drives, DOS 3 and the XLD did things the
absolute wierdest way.

Since the XLD had a double-sided (DS) drive, each side of the disk
was treated like a separate drive. Yes, with DOS 3 and your XLD,
your single, built in drive was actually D1: and D2:. The reverse
side had it's own directory. So if you had two DS drives in your
XLD, then you had D1: to D4:. Expanding on that, DOS 3 supported 8
drives like DOS 2 did.

I suppose you could have 8 drives, if Atari ever released a 1055
(?) DS drive. Or one could have an XLD with two drives, and
daisychain 4 1050s...

The internal XLD drives were alot faster, as they were parallel,
not serial like the 810/1050 drives.

Myself, I started with DOS 2, then DOS 3, tried DOS 2.5 then went
back to DOS 3. I got DOS 4, but unless you have three drives, it
was a pain. Actually, DOS 3 works better with three drives, D1: for
the system disk, and 2 and 3 for files and copying.


-- 
the good guys!               Sakura-mendo, CA

      Internet:  mfolivo@sactoh0.SAC.CA.US