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68k Macs: Does System 7.5.5 offer any advantages?


Well-known member
AFAIK, System 7.5.5 mainly offered PPC updates for 7.5.3, concentrated heavily on 68k emulation bugs and on new PPC Macs of the time that needed System software support.

Were there any significant fixes in 7.5.5 for 68k Macs? I ask because I have 7.5.3 newly installed on an SE/30 (runs it well), and I don't want to gum up the works with superfluous "feachers."



Well-known member
I have 7.5.1 on my SE/30. Works well enough, I never felt the need to update to .5

Apparently, the Secret about box game only works on 7.5 (ie only on .0 and does not work on subsequent versions)...



Well-known member
A long time ago, I made the Pong game into a stand-alone application, if anyone wants.



Well-known member
I just found this on TidBITS. 68k references or potential references are highlighted in blue:

"The 7.5.5 Update does not contain a plethora of new features, cool gizmos, and funky icons nestled in your System folder. Instead, the update is primarily a set of under-the-hood patches, fixes, and updates to System 7.5.3, including important updates to Virtual Memory, the SCSI Manager, LocalTalk and Ethernet networking, as well as a number of fixes for specific types of Macs. In addition, System 7.5.5 includes a welcome fix to the Modern Memory Manager that eliminates one cause of the infamous "Type 11 errors" on all Power Macs.

The primary features of the 7.5.5 Update are as follows:

    Improved Virtual Memory: System 7.5.5 includes significant changes to Apple's built-in Virtual Memory; the result should be improved performance when using and switching between applications or documents that require large amounts of RAM. Also, several potentially-crashing bugs were fixed, and changes that had previously been made for Virtual Memory on Power Macs were rolled into the 68K version. Macs should boot faster using the new Virtual Memory code, and Power Macintosh applications should launch more quickly. Please note that these fixes only apply if you use Apple's built-in Virtual Memory: if you use RAM Doubler or another third-party product for virtual memory, none of this applies.

    SCSI Manager: The SCSI Manager includes a number of low-level fixes to problems that could result in hangs and crashes on Power Macs.

    Code Fragment Manager: Changes to the Code Fragment Manager on Power Macintoshes should allow code libraries to load better in tight memory situations, which should be useful in improving the performance of PowerPC applications and games on entry-level Performas and other systems. (There are no changes to the 68K version of the Code Fragment Manager.)

    The System 7.5.5 extension set in Extensions Manager now correctly includes all QuickTime 2.5 extensions.

    Better-behaved background applications: In a very welcome fix, a long-standing bug with multiple background applications and the Process Manager has been fixed on all Macintosh models - basically, the system would hang if two or more background applications made a specific, common Toolbox call (MaxApplZone). Though this problem was well-known and well-documented, it's been lurking for years and still catches developers (and users!) by surprise. Faceless background applications include things like the File Sharing extension, Microsoft OLE, and numerous helper components of other applications and utilities.

    Fixes for machines which support the Infrared Remote Control, including Macs with the Apple TV Tuner.

    Correct IR Talk control panels and drivers for all machines supporting IR Talk. System 7.5.3 Revision 2 didn't include these items, resulting in varying "clean" installations of the IR Talk software.

    Improved Math routines: System 7.5.5 contains new, more efficient math routines, which might produce a slight performance improvements in some applications using these routines. However, these new math routines will also cause those applications to use 23K more memory (see below).

The System 7.5.5. Update also includes a number of machine-specific fixes:

    Fixes for a hang in the 68K emulator (and File Manager) on the PowerBook 5300, 2300, and PCI-based Macintosh computers.

    Ethernet fixes for 5400/6400-series computers that should improve communications on busy networks. (There's also an obscure LocalTalk fix for 5400/120s being used both as a server and a Remote Access server.)

    A problem initializing the PCI bridge chip on fast (180 MHz or faster) PCI Macs has been addressed, and the systems should now start up "more reliably." Further, these machines now correctly format floppy disks (they weren't waiting long enough for the formatting to complete), and floppy disk-related hangs on NuBus-based Power Macs have been fixed.

    All machine-specific fixes included in System 7.5.3 Revision 2.0 (see TidBITS-332)."

I am interested now in that central paragraph, as neither Virtual Memory nor Math Routines matter for my purposes. As I understand it, however, the "call" in question has implications for memory fragmentation in the old versions of the Macintosh operating system, so this might make it worthwhile to install the update.

Can anyone elaborate on the bug referenced? I am no programmer.

Full piece here: http://www.nzdl.org/cgi-bin/library.cgi?e=d-00000-00---off-0tidbits--00-0----0-10-0---0---0direct-10---4-------0-1l--11-en-50---20-about---00-0-1-00-0-0-11-1-0utfZz-8-00&a=d&c=tidbits&cl=CL1.1&d=HASH011da4427147d071a5359625.5



Daring Pioneer of the Future
Staff member
7.6.1 is my personal favorite for anything that'll run it, but with the opentransport, appletalk and appleshare updates available on S7T http://main.system7today.com/updates/75x_68k.html as far as I know both 7.5.3 and 7.5.5 should be able to talk to IP AppleShare servers, if you were interested in such a thing.

7.5.5 isn't really a major update to 7.5.x and my long standing thought on this is that if you're going to run these versions, there's no good reason not to be on the terminating version of the family. (7.1/pro, 7.5.5, 7.6.1, 8.1, 8.6, 9.1/9.2.2)

To add, personally I'm hesitant to install 7.5 on my personal systems. If your hardware is good enough to run 7.5.5 you'll probably be able to run a stripped out 7.6.1 install. If not, you might consider adding what you need to a 7.1 installation instead.

At worst, you could continue on with your current configuration and then make changes if you encounter problems. I haven't seen the error you've highlighted above, I'm sure it was something that cropped up when people were heavily daily driving 7.5-era Macs in the '90s, and probably occurrences of it fell off as people started having more hardware and using the older stuff more lightly/secondarily.



Well-known member
Having run both 7.5.3 and 7.5.5 on my Centris 650, I feel that if you are running 7.5.3, you might as well upgrade to 7.5.5.  7.5.5 performed the same as 7.5.3 did on my Mac.  7.5.5 was a nice sweet spot for me because 7.1 wasn't compatible with one of the apps I wanted to run (it needed 7.5.3 or above) and I didn't need the features of 7.6.1 or 8.1.



Well-known member
As an aside, I wish we could get the type of info on updates as was found in beachycove's post above for the Mac OS today. Instead, all we get from Apple is "Added new emoji" and other such useless nonsense when looking for system update info.



Well-known member
I wish we could get the type of info on updates as was found in beachycove's post above for the Mac OS today
<cynical knee-jerk> "for paying, registered, background-checked, devoted developers only—the little people needn't bother themselves with such trifles." </cynical knee-jerk>



Daring Pioneer of the Future
Staff member
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Well-known member
the cynical answer is that Apple hasn't fixed bugs in over a decade.
The last version where I think Apple genuinely cared about fixing bugs and optimizing code (at least publicly) was probably Snow Leopard.

Almost every version since has seemed to be much more hit or miss (possible exceptions include Mavericks and Sierra, both of which were actually reasonably good, stable versions at release in my experience).




Daring Pioneer of the Future
Staff member
In reality, it seems like every two or three versions gets tagged as a bugfix or quality of life fix release. Mountain Lion and High Sierra come to mind specifically. There have been long-standing problems fixed in OS X over the years. Somewhere int he 10.9/10/11 era, a really long-standing memory bug had been fixed, which up to that point had been forcing weekly-or-more reboots of my Mac mini as it ultimately ran out of memory and began swapping really badly.

I've mentioned this elsewhere but I suspect the literal entire Mac user and developer community if Apple hopped up on stage at WWDC this summer and announced literally nothing. Just. bugfixes for the next year. (This year in particular it would have the effect of implicitly extending further official security patches support for the 9-11 year old Macs that can only run up to High Sierra.)

Really, I feel like the biggest problem is most people feel like Apple last cared around the Snow Leopard era is because Snow Leopard, like Windows 7 represents roughly speaking the start or "before" state of a big shift in computing from ~2010-11ish to today.

This would actually be a good thing for me to blog about separately from here, because I've been thinking about this kind of thing myself. 2010-2011 is when Office 365 and Adobe CC were both released, it's when the Office Web Apps first came into being. iPad. Chromebooks. Google Docs were still relatively new (not brand new: writely started in 2007 or 2008 and was the first of a couple different web-based application experiments that have since come and gone), Dropbox was new in 2007, before which "file syncing service" literally wasn't a thing. In 2010 neither Mac nor Windows' built-in search functions hit the Internet at all. Computers still ran passably off of conventional spinning disks. AWS existed, but only barely. GCE and Azure outright didn't exist until later. Heck, 2009ish was just before Apple started re-engineering all their software, and before they dropped a bunch of software products off the roster. (RIP Aperture, iWeb et al) Small Business Server 2011 and OS X Server 10.6 still existed. Lots of other things, I'm sure.

It's clear a lot of people are using Windows 7 and Snow Leopard more as a stand-in for going back to "before all those changes".