Dev Conference 89
Volume Number: 5
Issue Number: 7
Column Tag: Editorial
Developer Conference Report 
By David E. Smith, Editor & Publisher, MacTutor
System 7.0 Detailed
Apple Computer Inc. previewed its new System 7.0 software direction to an
estimated 1,500 software and hardware developers at the Worldwide Developers’
Conference in San Jose on May 9, 1989. The new version represents what Apple calls a
“feature release”, which means Apple wants all users to upgrade to this version. It
will be compatible with all Macintosh computers from the Mac Plus and up, but only
68030 based machines or those using the 68020 with a PMMU will have virtual
memory capability under System 7.0. This version will shut the door on the older Mac
128K and Mac 512K machines, making the Mac Plus the official bottom of the product
line, if it isn’t already. To stay in the game, all users should plan on upgrading their
Macs to the functionality of a Mac Plus. Beyond that, there is the question of whether a
shop should upgrade all their machines to at least a 68030 based machine. Both the SE
and the Mac II offer upgrade paths to the corresponding SE/30 and Mac IIx machines.
Go Buy Some RAM
In addition to having at least a Mac Plus machine, System 7.0 requires at least
two megs of RAM to run. So plan now on attending a MacWorld Expo and buying more
memory. Show prices typically run $150 per megabyte. Future Macintosh computers
may have a ROM upgrade as well, allowing them to work with System 7.0 with only one
meg of memory by putting more of System 7.0 in ROM. Both the SE/30, IIx and IIcx
have ROM SIMM card slots to allow for a future ROM upgrade. Apple intends to move
it’s entire product line to System 7.0 so they will find a way to make it work as
cheaply as possible for their production units.
New Mac Rumors
The Apple press release for the conference makes mention of the fact that “Apple
expects to continue to offer an attractive low-end product with System 7.0.” We leave
it to the reader to guess what that means. Several comments were made that a low-end
Macintosh is coming but it is hard to imagine what that might be although rumors
suggest Apple has already figured out how to improve on the Mac IIcx and make it
cheaper to build. Rumors have also suggested a new high-end Mac IIcx running at 25
mHz is due shortly. And the fact that the next Mac World Expo in San Francisco has
been pushed back from January to next April suggests that Apple has some great new
product to release that will not be ready until April. Put all this together and you can
probably conclude the following:
• New low-end Mac at the Boston Expo?
• New high-end 25 mHz Mac IIcx Fourth Qtr.?
• Lap-top Mac at the San Francisco Expo ’90?
In the next twelve months Apple will release a low-end Macintosh and a 25 Mhz
Mac IIx of some sort. These two products will compliment what Apple is calling “the
mid-range” of the product line, the heart of their expected sales in the next 18
months, the Mac IIcx and the SE/30. Then in April, figure that Apple will release the
long-awaited lap-top Mac. But if the portable comes out as a wimp machine with only a
68000 in it, then it will bomb. It better be at least a 68020 with a PMMU or it won’t
fly. The world does not need a battery Mac. The world needs a moveable Mac that really
does fit under an airline seat!
Core Technologies
The main parts of System 7.0 (read the stuff that Apple is committed to getting
done on time) are the virtual memory, IAC, outline fonts and improved printing. The
memory manager and other system software have been re-written to be 32-bit clean
so that System 7.0 will include full 32-bit addressing. This will allow users to plug in
4 megabyte SIMM boards into the Mac motherboard for 32 megs of on-board RAM.
Amazing isn’t it? The physical memory limit will move out from the current 8 megs to
128 megabytes of RAM with a virtual address space of up to 4 Gigabytes. To make sure
your applications are “32-bit clean”, see technical note #212 & 213. Basically, you
don’t go around the memory manager by manipulating handles directly or trying to use
the top 8 bits in a handle you have assumed to be only 24 bits of address.
Some of the “fixes” Apple had to do to the memory manager to make it 32-bit
clean was to move the flag bits out of the top end of the master pointers, change the
block header format and size, and change the zone header format and size. They also had
to change the interface to the CalcCRegion in Quickdraw for custom controls (CDEFs),
as well as clean up various OS, toolbox, Finder and MultiFinder problems. A lot of
late-night soda pop didn’t hurt either!