Apple Developer preview beta releases of System Software 7.0, code
named "Big Bang".

Under a running development Mac OS, various build version numbers are
often differentiated by a replacement of the standard Macintosh menu
title "Special" with a unique word beginning with the letter "S" - for
example; "Stereophonic" instead of "Special".

 * DL #1: System Software 7.0a9 May 1990 ? "SanJose", as a Mini vMac
   compatible ISO image file in a zipped archive. A late Alpha
   release, it has on-board installers and alternative Disk Copy 4
   disk install images. Also includes HyperCard 1.2.5 for reading the
   included stackware documentation. The mounted name of this CD is
   "Big Bang".

 * DL #2: System Software 7.0b1c5 Oct 1990 ? A candidate release of
   Beta 1 taken from the "Bayou Briefing" CD located [here][1].
   Distributed on 800k Disk Copy 4 images.

 * DL #3: System Software 7.0b1 Oct 1990 ? "Sculley/$culley" as an
   ISO image file in a StuffIt .sit archive. Great for adding to an
   emulator's GUI to mount, e.g.; Basilisk II (running as an '030
   Mac).
First beta preview release of 7.0 ? The Apple menu's "Puzzle" game is
of a picture of [John Sculley][2].

 * DL #4: System Software 7.0b1 Oct 1990 ? "Sculley/$culley" as a
   Mini vMac compatible ISO image file in a zipped archive.

 * DL #5: System Software 7.0b4 Feb 1991 ? "SuperBeta" which is also
   the name of this CD ISO when mounted. A Mini vMac compatible ISO
   image file in a zipped archive.
   * Note: International versions of 7.0b4 in Dutch, French, Italian, Spanish and Swedish are located on the [System Software 7.0 Golden Master CD][3].

Compatibility
Architecture: 68k

68k

System 7.0 requires 2MB RAM which excludes Macs earlier than a Mac
Plus.

The ISO images marked "Mini vMac compatible", are mountable in a Mini
vMac Plus, or SE, SEfdhd, and Mac II variation builds. Extract and
drop the ISO into a running Mini vMac window to mount.

If wanting to install SSW 7.0 on Basilisk II, it is likely that B2
should be set to emulate an "030" CPU Mac, as '040" Macs weren't in
production during this period of Macintosh development.

DL#1: predates Apple Events and TrueType fonts ? Imagine that.
I was only able to get StuffIt Expander version 2 working correctly in
this release.

DL#2 - #4: TrueType fonts and Apple Events are more prevailent in Beta
1.
The ISO also includes full installs of [HyperCard 1.2.5][4] and
HyperCard 2.0 ? Some of the stacks on this CD require Version 2.0 to
view them.
The Mac "Special" menu title will randomly switch between Sculley and
$culley during reboots.

DL#5 includes a full install of HyperCard 1.2.5 and a "[Magic
Edition][5]" of HyperCard 2.0v2 along with a subset of the version 2
Stacks.

  [1]: http://macintoshgarden.org/apps/apple-internal-summit-conference-cds-1989-1994
  [2]: https://en.wikipedia.org/wiki/John_Sculley
  [3]: http://macintoshgarden.org/apps/mac-os-70-golden-master-release
  [4]: http://macintoshgarden.org/apps/hypercard-125
  [5]: http://macintoshgarden.org/apps/hypercard-player-v21-magic-edition