Re: Happy 30th Birthday to Disk ][ and Apple DOS

[pausch@saaf.se (Paul Schlyter)]

In article <g54eu9$fm7$1@registered.motzarella.org>,
jon  <jon@nowhere.com> wrote:
>The Disk ][ wasn't the first disk drive, but it was the first aimed at 
>the man in the street, it was probably the first mass market digital 
>storage device (5 years before CD).

Nah - the first "mass market" digital storage device was the audio
cassette recorder, some of them being modified explicitly for digital
storage for a specific type of computer.  The Commodore PET even had
audio cassete storage built into the cabinet.

>It transformed the Apple ][ from a geek toy into a real computer 
>solution and put the A2 ahead of the competition like the CBM PET and TRS-80

Dunno about that either - both PET and TRS-80 had floppy disk storage
too, as well as a number of CP/M computers from that time.  CP/M even
*required* disk storage of some kind.  No, what put the Apple ][ ahead in
the competition was its open architecture, which created a third party
market which soon made lots of hardware and software available for the ][.
And the entry of Apple ][ into the business market was due to one single
software package:  VisiCalc ....

>Apple DOS was just as much an inspiration for MS-DOS as the the 
>Macintosh had been for Windows.

Bzzzt - wrong!

The major inspiration for MS-DOS was definitely CP/M-80!  The system interface
of MS-DOS ver 1 was pretty much a copy of the corresponding interface of
CP/M-80.  Remember the FCB (File Control Block)?  MS-DOS used an FCB layout
which was almost identical to the FCB layout of CP/M-80, while Apple DOS
used a completely different layout which wasn't even documented.  Remember
the 8+3 filename limit of MS-DOS?  That limit was directly inherited from
CP/M-80, as well as the convention of using the last 3 characters of the
filename as an indicator of the "file type" - this was a convention though,
MS-DOS and CP/M were both really typeless file systems.  Apple DOS on the
other hand just had a 32 character limit of filenames, allowing embedded
spaces in the filenames (which was illegal in both MS-DOS and CP/M) but
lacking a convention correlating the end of the filename with some "file type".
Instead Apple DOS was a typed file system, with 8 defined file types:
B, T, A, I, R, S, "second A", and "second I".  Of these only the first four
were frequently used, the fifth, "R", were used by the Apple DOS Toolkit
for relocatable object files, and the remaining three were used only rarely,
or not at all.

Apple DOS didn't even have a decent command line!  Only a very restricted
syntax of the command line was allowed by Apple DOS - other needed input
parameters had to be obtained though a user dialogue by the application
itself, or perhaps through some data (text) file.  Compare this with the
very flexible command line interface of CP/M (which was directly inherited
by MS-DOS): after the name of the executable file you could type almost
anything you wanted.  CP/M and MS-DOS didn't object, it simply passed it on
to the application and then it was up to the application to try to make sense
of the command line, and to determine whether it was legal or illegal.


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Paul Schlyter,  Grev Turegatan 40,  SE-114 38 Stockholm,  SWEDEN
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