markv@dartvax.UUCP (06/02/87)
<...>
The May 25 issue of InfoWorld reports that Central Point
Software has discovered two bugs in Macintosh ROMs ("Developer
Finds 2 Bugs in Mac ROMs", p. 25). The first bug is in the old
(Mac 512KE/Plus) 128K ROMs, and can cause file tags to be
incorrectly overwritten, making file recoveries difficult. The
second bug affects only the Mac SE with two floppy drives.
According to the story, "...the upper disk drive motor is
unnecessarily turned off, slowing operations on that drive while
the motor is restarted..."
Well, I've had my dual-floppy SE for about a week now, and I
did notice that the upper drive seemed slower, and also sounded
somewhat different than the lower drive. At first I thought this
was just my imagination, but the InfoWorld story prompted me to
try a quick benchmark. I performed the following simple
sequence on each drive: powered up the machine, inserted a disk
and timed until the desktop was completely displayed, started
the Font/DA mover and timed until the fonts were displayed,
clicked the DA button and timed until the DA's were displayed,
then quit and timed until the desktop was redrawn. The times
are listed below:
Lower Drive Upper Drive
----------- -----------
Disk insertion to desktop: 17.4 25.3
Start Font/DA mover: 6.2 10.4
Click on DA button: 4.9 8.4
Quit to desktop: 11.4 16.8
(note: All tests performed with System 4.0/Finder 5.4, with no
disk cache)
As you can see, disk access in the upper drive is 50%-70% slower
than the lower drive. I find this somewhat distressing.
In summary: AARRRGGH!!!
I find it hard to believe that this behavior went unnoticed at
Apple before the machine was released.
The InfoWorld article goes on to mention that Central Point has
worked around the bugs in latest version of Copy II Mac (6.5).
This implies that there IS at least some sort of workaround.
Apple people on the net: will there be a quick patch (i.e.,
something besides a ROM upgrade) to circumvent this problem
distributed in the near future? (maybe in the new System
release?)
--
Mark Vita
markv@dartmouth.edu
{decvax,cornell,linus,astrovax}!dartvax!markvdgold@apple.UUCP (06/03/87)
In article <6387@dartvax.UUCP> markv@dartvax.UUCP (Mark F. Vita) writes: >The second bug affects only the Mac SE with two floppy drives. >According to the story, "...the upper disk drive motor is >unnecessarily turned off, slowing operations on that drive while >the motor is restarted..." >... >Apple people on the net: will there be a quick patch (i.e., >something besides a ROM upgrade) to circumvent this problem >distributed in the near future? (maybe in the new System >release?) The appropriate people are aware of this bug (and were before the InfoWorld article). It will likely be fixed by a patch in the next System file (that's not my department, so I can't make promises). In the meantime, the best thing to do is turn your RAM cache on; if you're not using Switcher, a good setting is 192K or 256K (depending on how much app memory you need). This will mask the effects of the bug. -- David Goldsmith Apple Computer, Inc. MacApp Group AppleLink: GOLDSMITH1 UUCP: {nsc,dual,sun,voder,ucbvax!mtxinu}!apple!dgold CSNET: dgold@apple.CSNET, dgold%apple@CSNET-RELAY BIX: dgoldsmith