#TECHTOOL PRO REVIEW MAC MAC OS#
#TECHTOOL PRO REVIEW MAC INSTALL#
#TECHTOOL PRO REVIEW MAC UPDATE#
#TECHTOOL PRO REVIEW MAC MAC#

#TECHTOOL PRO REVIEW MAC INSTALL#

Install or otherwise come upon a fresh, clean installation of OS 7.6.1 for All Macs (Minimal is just fine).

Fixing the Problem Method 1: Replace the System File This matter is discussed in the TechTool Pro 3 review. If i hear anything on this topic from them, i’ll post or link to the information (as permitted) from here.Įspecially interesting, and disturbing, is that TechTool Pro fails to detect problems in this clearly damaged System File. Since it appears that TechTool Pro 3 is still for sale, i am hoping that once MicroMat is aware of my new findings, they will take action to ensure that anyone wishing to run TTP on 680x0 Macs from a bootable CD will be able to do so without unnecessary Type 1 errors. I am guessing that 1) I was busier then, 2) I was not getting paid to do this, as i used to be at Apple, and assumed that someone who was getting paid would do this time-consuming sleuthing. Why this didn’t occur to me to try several years ago, when MicroMat would have been able to fix it, i don’t know for sure. Finally, i made a CD-R copy of my TTP CD-ROM, identical except for the one-byte change from F9 to FF: No Crashes when running under OS 7.6.1.

I did this several times with both a CD all-Macs OS install and an OS originally installed on the IIsi HD specific to the IIsi. I re-edited it to be F9 again: the crashes returned. I edited the crashing copy of 7.6.1 copied from the TTP CD-ROM so that the byte was FF: the crashes went away. There was 100% correspondence between the presence of F9 and Type 1 crashes, and FF and no crashes.

#TECHTOOL PRO REVIEW MAC MAC#

I checked the 5 or 6 other OS 7.6.1 System files i currently had available on various Mac HDs and on the AlSoft DiskWarrior 2.1.1 CD-ROM: all of them had the byte FF at that same position. I checked the three MicroMat-made TTP CD-ROMs i have (for TTP 2.5.4, 3.0.6, and 3.0.9): every single one had the byte F9 at offset 2910 in the gpch ID=667 resource. Specifically, a one-byte difference in the “gpch” resource between working and crashing versions of the file. After many, many hours of thought and experimentation, i finally found the problem: a defect in the System file of OS 7.6.1 on the TechTool Pro CD-ROM. There were several false leads and dead ends. Next, i spent literally a couple of days trying experiments comparing the working and crashing copies of OS 7.6.1, and shuffling parts between them to try and narrow down the root problem.

#TECHTOOL PRO REVIEW MAC MAC OS#

The problem was not related to the copy of TechTool Pro itself residing on the CD, and was instead a problem with the copy of the Mac OS 7.6.1 on the CD.

The problem was not specific to something else on the CD.

Sure enough, when running from the OS 7.6.1 copied from the TTP CD-ROM, Type 1 crashes happened all over the place, in the same way and under the same conditions as when booted from the CD. I knew that when running from the stock 7.6.1 on the HD, Type 1 crashes were extremely rare (if indeed they happened at all… i don’t remember). It occurred to me to try copying the OS 7.6.1 off the CD-ROM onto my IIsi’s internal hard drive (hereinafter HD), to see if the crashes would still happen.

It sometimes seemed difficult to do anything running under 7.6.1. Running from OS 7.5.5 on the CD rarely crashed, and when it did, the crashes were usually not Type 1. I had long know that the problem only occurs when the computer is running from the Mac OS 7.6.1 on the CD.

#TECHTOOL PRO REVIEW MAC UPDATE#

Having become annoyed at this situation during March 2005 testing for an update to this review, i decided to take the time to look deeper into the problem. Sonic’s TechTool Pro CD-ROM Fix Type 1 Crash Fix History & The SituationĪs discussed in the individual reviews for TechTool Pro versions 2 and 3, Type 1 crashes when booted from the TTP CD-ROM have been very frequent, esp.

Techtool pro review mac