[comp.sys.mac] New System and Upgraded 512E's

nicky@cup.portal.com (07/09/88)

Any more information about incompatibilities between sys 6.0,
the DOVE upgrade and SCSI disks
would be appreciated.  I recently connected my SuperMac DataFrame XP60 to a
friend's upgraded 128K (128K -> 512K,128k ROMS -> 1M, as far as I can
tell).  A few days later the disk ceased to work.  I did not originally think
the problem was with software but I'm anxious to find out if anyone else has
had similiar problems.  Another disturbing thing was to be told by the person
at ComputerWare that a bunch of DATAFRAMEs had just recently
come in for repairs.

c60a-6dd@web7c.berkeley.edu (Rob Pfile) (07/10/88)

In article <3265@polyslo.UUCP> dorourke@polyslo.UUCP (David M. O'Rourke) writes:
>  System 6.0 does not run on a 512Ke!!!  The sound manager, and hence the
>sound CDEV make use of the extra bytes that are present in the clock chip's of
>the new computers, i.e. the Mac Plus, SE, & II.
>  System 6.0 also contains a new Serial Driver that uses the some features of
>the *SLIGHTLY* different serial hardware present from the plus on.
>  So the bottom line is that you can't use 6.0 on a 512Ke, even if you have
>the memory to do so.

 Well, Even though I knew that the System 6.0 was not supposed to work
with my Dove 1meg 512e, I went ahead and tried it anyway...

 It seems to work fine, although as I expected, my Dollars & Sense
4.1b does not work any more. That's OK, I just have not had my father
send the update up to me. As I have heard, Excel does not work
either...

 If the problem is the Sound Manager itself, then there is nothing I
can do about the missing memory, however, my Sound CDEV seems to be
working just fine as it is. I was under the impression that it was
only the Sound CDEV that used the extra bytes, but I guess not...

 On a side note, I reformatted my HD20SC under System 4.3 (the last
release) with the second release of the SCSI accelerator at a 2:1
interleave factor. The read time (DiskTimer ][) was improved from 158
down to 96, but I suppose that since the Accelerator does not patch
the write code in the driver, the write time skyrocketed to 388 for
the usual 100 24Kb writes. Oh well... According to the docs it was not
even supposed to work with the hardware in the HD20SC...

 And, of course, it bombs out at boot time when running system 6.0
with the accelerator...

Rob



________________________________________________________________________________
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bill@procase.UUCP (07/13/88)

In article <3265@polyslo.UUCP> dorourke@polyslo.UUCP (David M. O'Rourke) writes:
>		...
>  System 6.0 does not run on a 512Ke!!!  The sound manager, and hence the
>sound CDEV make use of the extra bytes that are present in the clock chip's of
>the new computers, i.e. the Mac Plus, SE, & II.
>  System 6.0 also contains a new Serial Driver that uses the some features of
>the *SLIGHTLY* different serial hardware present from the plus on.
>  So the bottom line is that you can't use 6.0 on a 512Ke, even if you have
>the memory to do so.
>
>***Flame on!!!!!!!
>		... (flames deleted)

Well, I've been on both sides of this issue now (having spent most of my
career working for hardware manufacturers and now being the owner of an
apparently obsolete 512KE). There are a lot of good arguments on both sides.

There are many good reasons why a manufacturer may want to cease support of
an old machine; these reasons may not always be known or understood by the
user community, they may even be secret.  Anyone who has worked for a computer
manufacturer knows this.  As the number of different old machines increases,
the effort to support them all becomes increasingly burdensome.  Old machine
support takes time and manpower, sometimes lots of time and manpower.

Obviously, owners of those old machines want support forever.  Owners of old
Macs can also justifyably claim some extra credit for supporting Apple in the
bad old days of the 128K.  It seems churlish and mean to cut them off now that
the Mac is doing so well.

Its a trade-off.  The manufacturer makes the decision.  He must weigh the
benefits of putting his engineering effort
into new stuff for new machines versus continuing support for old machines.
There is never enough engineering staff or budget to do it all.
Users must understand that their old machines can not be supported forever.

The trick, it seems to me, is choosing a psychologically appropriate time
to cut off the old machines.  And making it clear to the users why it was
necessary and what the benefits to the community as a whole are.

In this particular case, I'm not sure what Apple's reasoning was.  I'm
willing to withhold judgement.  Can comments, Apple?
-- 
  Bill Arnett             {ucbvax!tolerant,hplabs!hpda}!procase!bill
  proCASE Corp., Santa Clara CA
  408/727-0714