jmacz
Well-known member
I was poking around MacsBug yesterday on my Quadra 800 and noticed the following when I execute a heap check:

Looks like an issue with heap zone #2. This was using MacsBug 6.6.3 on a Quadra 800 running System 7.5.5. I tried a few other disk images I had (another System 7.5.5, a System 7.1.1, etc) and all report the same thing. MacsBug 6.5.4 also reports the same thing. Happens with / without extensions enabled. The same disk images run on a IIci does not show the heap zone issue.
Since the same disk images work fine in the IIci, I thought perhaps this was a hardware issue with my Quadra 800 (extended MacTest Pro memory checks are all good) and the machine is fully functional with no issues aside from this weird message in MacsBug.
I then decided to check all my machines. My two IIcis, my SE/30, my IIfx, all report no issues with the same disk images.
BUT my Quadra 700 and my PowerBook 540c report the same heap zone issue with heap zone #2. The memory address on my Quadra 800 and 700 are identical (0x000021d0). The memory address on my PowerBook 540c is slightly higher (0x00002800). But in all three cases it's the same message regarding heap zone #2 which is "The heap at xxxxxxxx is bad. Nonrelocatable block: Pointer to zone is bad".
The commonality is obviously my 68040 machines are showing this. My 68030 machines are not.
Is this a known quirk with MacsBug or is there something wrong here that is plaguing three of my machines (my 040's) but not my others (030's)? I thought I'd ask to rule out a simple explanation before digging further.

Looks like an issue with heap zone #2. This was using MacsBug 6.6.3 on a Quadra 800 running System 7.5.5. I tried a few other disk images I had (another System 7.5.5, a System 7.1.1, etc) and all report the same thing. MacsBug 6.5.4 also reports the same thing. Happens with / without extensions enabled. The same disk images run on a IIci does not show the heap zone issue.
Since the same disk images work fine in the IIci, I thought perhaps this was a hardware issue with my Quadra 800 (extended MacTest Pro memory checks are all good) and the machine is fully functional with no issues aside from this weird message in MacsBug.
I then decided to check all my machines. My two IIcis, my SE/30, my IIfx, all report no issues with the same disk images.
BUT my Quadra 700 and my PowerBook 540c report the same heap zone issue with heap zone #2. The memory address on my Quadra 800 and 700 are identical (0x000021d0). The memory address on my PowerBook 540c is slightly higher (0x00002800). But in all three cases it's the same message regarding heap zone #2 which is "The heap at xxxxxxxx is bad. Nonrelocatable block: Pointer to zone is bad".
The commonality is obviously my 68040 machines are showing this. My 68030 machines are not.
Is this a known quirk with MacsBug or is there something wrong here that is plaguing three of my machines (my 040's) but not my others (030's)? I thought I'd ask to rule out a simple explanation before digging further.