Re: The DOS 3.3 SYS.COM Bug Hunt

Lawrence D'Oliveiro <ldo@nz.invalid> writes:

On 25 Feb 2025 02:19:13 -0400, Mike Spencer wrote:
 

Learned all the basic principles of how computers operate --
intentionally obstructed from day 1 by Apple for Mac, dismally more
arcane for then-current 386.

 
The "Inside Macintosh" series had all the details. Volumes I and II
covered the software APIs, while Volume III described the original
Macintosh hardware: the video buffers, sound buffers, vertical refresh
interrupt, floppy interface, Z8530 serial controller chips, the lot.
Volume IV updated all that for the Mac Plus (with SCSI!).

I borrowed an Apple ][ (sic) in 1980, my first computer "experience"
since 1964 and punch cards.  I was sold but I couldn't afford my own
just then.

Soon thereafter, Apple was ballyhooing the Mac so I borrowed a Mac for
a week, then went into the Apple Store and had a look:

    Me: So, how do you program it?

    AppleGuy:  What do you want to do?

    Me: Well, I want to write programs for it.

    AG: Yes, but what do you want to *do*?

    Me: Program? You know?  Like, write a program that the machine will
        run?

    AG: But what do you want to do?

       [Rinse & repeat ad naus.]

Never did get him to tell me how you program a Mac.  A bit later, from
a different source, I learned that you could buy a "programmer's
switch", a piece of plastic that you stuck into a hole on the back of
the machine where it presses against an already-present switch and
does $SOMETHING allowing you to, in some sense, "program". You also
needed a "application developer's kit", two or three hundred bucks
(early 80s $$) worth of Apple-proprietary disks.

This (to me, then) incredible horseshit caused me to permanently write
off Apple as part of Them, not Us and certainly not Me. More recent
cries of Unix-Under-The-Hood sounded great when I first heard about it
but, AFAICT, it's still wrapped in the same arrogance and hubris as
refelcted in the above anecdote.

Only a few years ago, a friend with a recent Mac called me for help --
I forget why.  Totally baffled by the Mac GUI interface, I told him if
he could get me an xterm, I could fix him up.  Took him 20 minutes to
figure out how to get a bare xterm up.  Then, working at Under The
Hood level, I fixed him up.


    We offer you a Perfect World. Just as long as you stay inside the
    yellow lines. Please stay inside the yellow lines.  The Armed
    Response Team thanks you for staying inside the yellow lines.

Those Z8530 chips were wonderfully versatile. Back when your Microsoft-
compatible PCs were struggling to do transfers beyond about 19200bps, the
Mac could do 230.4kbps, or even a megabit per second with external
clocking (e.g. for MIDI).

But who knew? "What do you want to *do*?" 

--
Mike Spencer                  Nova Scotia, Canada