Re: Apple II-Or Come on people, It's a 20 year old computer

[pausch@saafNOSPAM.se (Paul Schlyter)]

In article <sS_e5.9313$I76.570308@monger.newsread.com>,
Matthew T. Russotto <russotto@wanda.vf.pond.com> wrote:
 
> In article <8ippuu$de6$1@merope.saaf.se>,
> Paul Schlyter <pausch@saafNOSPAM.se> wrote:
> 
>} Possibly -- I never immensed myself into the architecture of the
>} Lisa.  I noted that, besides being expensive and slow, it also broke
>} a tradition from the Apple II:  the Lisa, and later the Mac, were much
>} more closed systems.
> 
> The Lisa wasn't closed-- it had slots (3 of them).  There were even a
> few cards available for them.
 
True -- however the Lisa was horribly expensive.  SUpposedly those cards
were quite expensive too.
 
>} Today, things have calmed down a bit: all modern computers use a GUI
>} of some kind.  The Mac has "opened up" a bit (I think), and it can
>} even read standard diskettes instead of using its own weird low-level
>} diskette format 
> 
> Weird?  If you were to read the low-level formatting of a Mac 800K
> or 400K 3.5" diskette, you'd find yourself in very familiar territory
> -- remember "D5 AA 96"? 
 
....if I would get as far as being able to read those D5 AA 96, that is.
You will NOT be able to do that with a standard floppy disk controller.
Which means there'll be great difficulties reading such diskettes on
anything but a Mac (or possibly an Apple II equipped with a 3.5" disk).
 
On the PC there were utlities to read and write various CP/M disk
formats.  Some of the better of those utilities could read a few
hundred different CP/M disk formats.  One common CP/M format was
always missing among all these utilities though: the Apple CP/M disk
format.  This was because of the weird low-level disk format which
was used by Apple but nobody else and which was impossible to read on
a non-Apple system (unless you added custm hardware just for reading
those disks).  Yes, this disk format made sense at an early stage,
because floppy disk controller cards became simpler and cheaper, and
there was no standardization anyway back then.  But as time passed
on, non-standard formats became more awkward.  That's why the Mac
changed from the GCR to the MFM low-level disk format: because it was
used by everyone else and enabled file transfer to/from alien disk
formats with only a software add-on.
 
-- 
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Paul Schlyter,  Swedish Amateur Astronomer's Society (SAAF)
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