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From: AWCTTYPA@UIAMVS.BITNET ("David A. Lyons")
Newsgroups: comp.sys.apple
Subject: DOS 3.3/ProDOS
Message-ID: <8806210243.aa00242@SMOKE.BRL.ARPA>
Date: 21 Jun 88 09:35:11 GMT
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X-Unparsable-Date: Tuesday 21 Jun 88 1:24 AM CT

>Date:         Mon, 20 Jun 88 00:31:35 EST
>From:         Murph Sewall 
>Subject:      Re: DOS/ProDOS

>The point is I am NOT anti-ProDOS.  Everything I've seen indicates it
>is a MUCH more sensible system for developing applications, but a lot
>of this "ProDOS is the ONLY way to go" chatter seems to be coming from
>people who arrived (and bought their software) after 1985.

True, ProDOS isn't the ONLY way to go.  If there's a reasonable
decision to make, I always say to go with ProDOS.  Certainly very
little NEW software is being developed for DOS 3.3, and it is
gradually dying out.  New stuff like AppleShare (file server) does
not support DOS 3.3, and as storage devices continue to grow, it
gets less and less reasonable to keep using DOS 3.3.  CD-ROMs would
be ridiculous, for example, addressed 400K at a time.

>How come there are so many ProDOS word processors and not one decent
>ProDOS text editor (WYSIWYGs make TERRIBLE text editors and besides
>they hog core with lots of "features" that a word processor needs but
>a text editor doesn't)?

Well, there's FreeWriter, and the ProDOS AppleWriter (is it still
being sold?).  Are those the kind you're looking for?  I suspect we
will see some more text editors being developed.  (I wouldn't mind
writing one some day, and some of my friends are inclined in that
direction, too.  Writing their own, I mean, not just wanting me to
write one!)

>Though I like hard disks for working storage and software, they
>aren't reliable enough to trust anything truly important to (hence
>the constant admonishions to back up the rascals).  Finished work
>belongs on disks (plural) anyway.  I can keep track of volume numbers
>as easily as pathnames, so two 400K volumes on a 3.5" disk isn't
>really a handicap.  My RAM-Charger just died; while RAM disks are
>truly neat, they are even less reliable than hard disks.

That's not very fair--I don't find hard drives to be less reliable
than other storage devices.  The reason backing up HDs is so
important is that you can lose a LOT of stuff all at once.  If your
power goes out while writing to the main directory on the hard
drive, you can lose everything on it (unless you want to spend a lot
of time recovering it and PROBABLY succeeding); it's not so big a
deal on smaller devices, since there's less data involved.

You should ALWAYS back up everything important.  I've had trouble
with 3.5 drives, 5.25 drives, RAM drives, and hard drives.  But I
back things up, and I've never lost much work.

[Sorry--I've lost track of who ">>" is; the person Murph was quoting]
>>2. no support for modern hardware such as eighty column displays,
>>   extended memory and interrupting devices such as the mouse
>Funny how well my 80 column card works with my DOS 3.3 applications; and
>I've got a number of 128K DOS 3.3 programs.

ProDOS supports the 80-column card to exactly the same degree that
DOS 3.3 does:  NOT AT ALL.  80-column support is completely up to
the applications you're running.

>>    4.  DOS has no consistent call interface; as a result, DOS
>>        was only reassembled once in its five-year life, as this
>>        would cause routine entry points to change, causing
>>        programs to quit working. As a result, all bug fixes
>>        consisted of applying patches to the existing code.
>That's more esoteric than I care to investigate, but it strikes me as
>peculiar that Diversi-DOS, David DOS, One-Key DOS, and ProntoDOS work
>so well.  I don't believe any of those are merely patches to the
>existing code.

Actually, all of those ARE patches to DOS 3.3.  *NOT* minor ones,
but still patches.  I wouldn't call them "mere" patches--they are
certainly significant and complicated.

>Programmers sometimes use undocumented entry points resulting in no
>end of trouble when the operating system changes [...], but it
>doesn't seem to be all that bearish for a really good systems
>programmer to keep the documented entry points where the
>documentations says they'll be.

Unfortunately, very little of DOS 3.3 was officially documented.
Apple documented the RWTS interface, which could read and write
SECTORS on disks.  It didn't provide any access to the file
structure.  The File Manager (FAM) was documented in places like
Beneath Apple DOS.  It is a fairly clumsy interface, and it wasn't
really sufficient to do all the things programmers wanted to do.  So
they quite understandably started using other, undocumented entries
to DOS.

The ProDOS MLI (Machine Language Interface) is slick,
well-documented, and leaves no good reason for programmer to code
around it.

>ARPA:   sewall%uconnvm.bitnet@mitvma.mit.edu       Murphy A. Sewall
>BITNET: SEWALL@UCONNVM                          School of Business Admin.
>UUCP:   ...ihnp4!psuvax1!UCONNVM.BITNET!SEWALL  University of Connecticut

--David A. Lyons  a.k.a.  DAL Systems
  PO Box 287 | North Liberty, IA 52317
  BITNET: AWCTTYPA@UIAMVS
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