[Kerberos for Macintosh]
Overview of Apple's direction with older Macintoshes
A view of the usability of older Macintoshes on the MIT campus.
The latest version of MacOS, version 7.5.5, will be the last to support Macintoshes without 32-bit
clean ROMs1. These are predominantly older machines and are the Plus, SE, SE HDFD, Classic,
Portable, PowerBook 100, Mac II, Mac IIx, Mac IIcx, SE/30 and LC2. Although most third party
software will not require the newer MacOS system versions for some time, it is a statement of direction
from Apple with regard to their active development for these older machines. In dropping new development
for this set of machines, Apple will be able to roll out more changes to the MacOS which they have planned
for some time.
Impact on IS efforts: This probably will not be felt heavily for at least another year. As stated
above, most software that works with these older machines will continue to do so, that is the developers
probably will not cut off development for some time. However, this point may happen sooner if these newer
versions of the MacOS become very popular. There is a strong chance of this in fact happening as the improvements
Apple is planning are greater than in previous system upgrades. One additional hitch in this equation is if
we are able to obtain a MacOS site license for the MIT community, our users will probably upgrade much more
rapidly than they are doing now.
Of the machines on the list, the ones that we probably need to worry about are the Mac II(x/cx)'s, SE/30
and LC. Although we do not have a very good list of how many of these machines are still active on campus,
they still probably represent a noticeable number of machines.
CFM-68K and SAP
The security portion of SAP requires the Code Fragment Manager in order to access the GSS shared library.
Although CFM is built into all Power Macintoshes, for the older 68K machines it is an optional install.
Even then, CFM-68K has a few requirements, 68020 or better processor, System 7.1 or higher and 32-bit
addressing turned on. This means that the older 68000 based Macs like the Plus and SE will never be able
to run SAP here and that those Mac II's and others from the list may not be able to run SAP securely.
The new networking architecture has similar requirements to CFM-68K except that it needs a 68030 or
higher processor. Open Transport becomes important to us in areas such as Tether where the next version
of the PPP client that we will be distributing will require OT. Tether software will still be provided
for older machines but no active development is being done for that version. This is a similar situation
software wise to Techmail-S in that we do not control the connection software used.
This information is being provided more as a heads up rather than a crisis point. The question for us
at or within IS now is how much this should affect our future development plans and how should we let
the customers know that some critical products, in house and third party, may not work on their machines.
Examples of the first point might include work with Cyberdog,
Apple's Internet suite based on OpenDoc and thus requires CFM-68K.
Apple is helping somewhat on the second point through their publicity about future versions of MacOS.
While solutions are still available for most of these older machines, active development for them is
beginning to cease and we need to decide how much effort needs to be spent on bringing them along with
Note 1: 32-bit dirty and 32-bit clean refer to the old style of memory address usage where the
high byte of a memory access was often used to carry extra information not related to the memory address.
This is known as 24-bit addressing or 32-bit dirty. 32-bit clean programs do not do this. The Mac IIci
was the first Mac with 32-bit clean ROMs. Apple never released a permanent fix for the effected machines.
Note 2: This refers to the original LC and not the LC II, LC III or LC 475.
Guide to the Age and State of older Macs
Machines where development is drying up and hard to support (all 68000 processors)
- SE HDFD
- Portable (the boat anchor)
- Powerbook 100
Machines where supporting, in the development sense, is getting harder. Some technologies work
while others do not. (Mostly 68020 and 32-bit dirty ROM machines)
[These machines have not been determined to work with SAP. From a paper requirements standpoint,
they would need a piece of software, Mode32 from Connectix, before working. However it has not been
determined if Mode32, CFM-68K Runtime Enabler and SAP are compatible.]
Machines that are starting to be considered the baseline for active development but performance
might be considered minimal (the majority of 68030 machines)
[These machines will technically function with SAP although performance will be poor.]
- LC II
- LC III
- PowerBook 140 - 180c
- PowerBook Duo 210 - 270c
Machines where development and performance is still active and reasonable (68040 and PowerPC processors)
Although 68040 based Macintoshes (Centris, Quadra, etc.) may still have some life left in them,
it is encouraged that you plan your upgrades to PowerPC based Macintoshes soon. Some third party
companies have stated already that future development will be for PowerPC Macs only. The most
notable of these are Microsoft starting with
MS Office for Macintosh 97. Some technologies
from Apple, such as QuickDraw 3D
and Game Sprockets, are also PowerPC only.
- Centris (all)
- Quadra (all)
- PowerBook 520/540
- PowerBook 190
- PowerMacintosh (all)
- PowerBook Duo 2300
- PowerBook 5300
- PowerBook 1400
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Last updated on $Date: 2003/11/18 21:58:16 $
Last modified by $Author: smcguire $