IIcx Time Problem

[Big Bird]

I'm in the process of setting up a Mac IIcx as a LocalTalk Bridge/IP Gateway, but it has a really strange problem. It will retain a time that you set in the Date & Time control panel, but no matter what you do, it will not KEEP time. That is, once you "set" the time, it doesn't count seconds up. The same time just stays there. Unlike the symptoms of a dead PRAM battery, the IIcx retains the exact time that you set it to, down to the second, and does not reset the time or date to 1904/1956/whenever. Could it still be a PRAM battery that's keeping it from counting time?

It has a fresh install of System 7.5.5 on a known good hard drive, RAM, video card, and network card. MODE32 is installed. There's nothing in the machine I can figure out that could be causing this. I've tried zapping the PRAM, of course, as well as trashing preferences, although that doesn't make sense with the fresh system install anyway. Pulling the hard drive, network card, RAM, and video card from the IIcx and dropping them into a IIci (and the HD into an LC III) fails to replicate the problem; both Macs count time as normal.

Has anyone seen anything like this before? Any ideas on what it might be? At this point, I'm down to a logic board or component-level issue, but I don't have another IIcx to test that theory easily, not to mention would sort of rather it be something else.

Thanks for the help,

Cody

 

[Quadraman]

I've heard a PRAM battery doesn't have to be completely dead to cause problems. I'm not sure as to the truth of it, though. It wouldn't hurt to put a new one in and see what happens.

 

[coius]

RTC Chip blown?

 

[wally]

...seen anything like this before? Any ideas on what it might be? At this point, I'm down to a logic board or component-level issue, ...

Umm, no, yes, and agree. Sounds like a hardware problem to me also. An easy second step while you are experimenting with the battery is to do a topside visual board inspection around the battery, crystal, 8 pin RTC chip if you have one right next to the crystal, looking for capacitor wet residue, corrosion, foreign matter shorting out the crystal, oscillator or the one second interrupt to the VIA interface chip. By the way, that RTC is where the PRAM lives also, so if it remembers mouse settings and other stuff maybe the chip is powered and backed up okay but the oscillator is not going, stopping time as it were. I think the VIA externally serial clocks the PRAM data in and out. If you have Guide to the Macintosh Family Hardware, Second Ed, see p144. I can walk you thru the pinouts if need be.

 

[Big Bird]

Thanks for the responses. As it turns out, disabling MODE32 causes the Mac to count seconds, but VERY slowly . . . about 3 seconds to every 1 second ratio. This seems to put an entirely new twist on it.

A visual inspection reveals no obvious damage or corrosion to the board level components around the battery. I did manage to dig up another IIcx, and I transplanted everything but the board into that machine. It has the same symptoms: time failing to count with MODE32 enabled, counting a second about every 3 seconds with MODE32 disabled.

I can't help but think this is unrelated to MODE32, as I and probably many of us have used it successfully on other machines, but for some reason, these two IIcxes seem to be stuck in a time warp whenever they address more than 8 MB of RAM. But I don't know what might be the actual cause of the change in symptoms upon disabling the extension.

 

[wally]

Simms loaded in full groups of four?

Any unusual extensions or control panels that might warrant a run with Conflict Catcher?

If interrupts were coming in fast and furious, maybe the time ones lose out?

Most curious...

 

[tomlee59]

I transplanted everything but the board into that machine. It has the same symptoms: time failing to count with MODE32 enabled, counting a second about every 3 seconds with MODE32 disabled.

Did "everything" include the pram battery? Either way, if you have a voltmeter, measure the battery voltage in operation. If it reads ok (say, 85% of nominal or better), then you can rule out the battery as the source of trouble.

 

[Big Bird]

Yes, the PRAM battery was included in the swap, but I had already replaced it with a new one in the original IIcx. I don't think the battery is the problem.

And yes, SIMMs are loaded in full groups of 4 matched sets -- 4 x 4 MB and 4 x 1 MB. If I remember correctly, it was only the Mac II that couldn't handle SIMMs >1 MB in the first four slots.

I like your fast and furious interrupts theory. In fact, I think it may be right on. But the vexing part is my inability to ascertain the source of these mythical interrupts. I know there's no unusual extension or control panel causing the problem because the problem is exhibited under a fresh 7.5.3 install.

So, to sum up: the problem occurs under a fresh install on two different IIcxes. The problem does not occur when the exact same drive is dropped into a IIci or LC III. This seems to eliminate a software problem, unless I'm missing something. Then, a fresh PRAM battery is being used with RAM that is confirmed good in a IIci and neither IIcx motherboard shows signs of physical corrosion or damage. This seems to decry the hardware issue. I'm at a bit of a loss here . . . :-/

 

[phreakout]

Big Bird, have you tried a different clock for that computer? Like, say, Superclock? Because I was thinking it could be the software for the clock in System 7.x. If not, do a really thorough search online regarding your problem to see if anyone in the past (outside 68kMLA) has had the same.

73s 8)

 

[wally]

...to ascertain the source of these mythical interrupts...

I'm having trouble imagining memory misbehavior that would not eventually cause a bomb. But I am beginning to wonder about the video card, network card, keyboard and mouse that were presumably common to the tests. Does the mouse point/track smoothly, and does running keycaps from the apple menu show any stuck repeating keys? If there is any choice of video resolution, does changing it change the time loss rate? Booting without the network card, does the problem remain? "Borrowing" another keyboard, mouse, video card and some other memory, and/or trying less memory are other possibilities.

 

[Big Bird]

phreakout:

Doesn't SuperClock just display the System 7 clock's time on the menubar? I've never actually used it because I've never actually cared about the time on the menubar, but that would be my guess. But not only that, since this machine is running as a server, it needs to have accurate time. The system time is the time that really matters, since it provides the foundation for time/date stamping and because applications just do API calls (I'm showing my Windows background; I don't know what this is called on the classic Mac OS) to the OS for the time.

wally:

This is exactly why I posted this on here. The keyboard, mouse, and video card were definitely common to both of the IIcx trials. I knew I'd forgotten something that should be obvious. I mean, it "shouldn't" be the problem since all have worked with other Macs, but you never really know until you try it and I'm grasping at straws here. I really wanted to use the IIcx for this project (don't ask me why, I'm not sure I could tell you exactly ), but I may have to end up switching machines. I'll swap the devices from another functional setup to try it tomorrow and post back. Thanks for the suggestions!

 

[Big Bird]

So, back in town and on a bizarre sleep schedule from time zone changes, I was finally able to work on the Mac again.

I tried a new keyboard, mouse, and video card from another working Mac setup, and the time problem continues. I replaced all the RAM with 1 MB SIMMs from a IIci, but no dice. I put in a new hard drive pulled from a IIci and tried booting with extensions on, then off, and both times, nothing. I can't seem to find anything that makes either of these IIcxes count time properly. I don't know if it's "good" news, but all of these attempts cause it to count 1 second for every 3 actual seconds, rather than hold time at a complete standstill.

Two different IIcxes now have:

• • confirmed good keyboard, mouse, and video card
  • fresh install of System 7.5.3 or installs of 7.1/7.5.5 on drives pulled from working Macs
  • new PRAM battery
  • RAM pulled from another working Mac
  • floppy drive disconnected
  • network card removed
  

What am I missing now? Any more suggestions before I have to pitch these machines back into storage? Anyone have a really cheap Quadra 700 for sale? :-/

 

[bigD]

Wait, you're saying you have *two* IIcx's doing this crap? Seeing as how you did everything else, it does seem to be a component level problem, but on two different machines? Hmmmm.....

I've run OS 7.5.x on a IIcx without problem, and I see that you've also tried 7.1, which I know runs fine too, but perhaps create a System 6 boot disk, unplug the hard drive, and see what happens?

 

[bigD]

And if nothing works, would you be willing to part with one of the IIcx's? I'm desperately trying to get my dead one to work. Hook a fellow Longhorn up!

 

[wally]

Were different power supplies tried? Or the original one moved to the second machine for testing? I'm thinking about /pfw power fail interrupts that when handled see power as ok again, but that monopolize interrupt handling time...these could be faulty /pfw signals from one bad supply, or good ones from two different good supplies that happen by their design not to be able to handle spike or dropout electrical noise unique to your lab...

Is there an unusual lab electromagnetic environment that could cause the normally 32768 Hz crystal oscillator to run in sync with some slower external humungous field instead? Like an NMR or MRI setup?

 

[Charlieman]

What happens if you set the year date to, say, 1997?

 

[Big Bird]

Several power supplies were swapped in and out, and since I'm doing this in a bedroom not in one of the chemistry labs at the university, I don't think there's any strange EMI. The date doesn't matter. All Macs have full support for the Y2K rollover up until the year 2019; it just sees the "7" or "07" as the year 2007. Plus, I always configure to show four-digit years, so that shouldn't be a problem. But I've sure tried it with the number of times I've reset the PRAM.

Strangely enough, when I boot into System 6.0.5, the time starts working. Then, rebooting the machine into System 7 or off of any hard drive I've tried in the machine, the time continues to work.

So I guess it's fixed? I'm not sure how or what I did. Although I'm worried it's going to stop working again after I leave it off for a while. I'm always apprehensive whenever I fix a machine without knowing what I did to fix it.

 

[Charlieman]

The date doesn't matter. All Macs have full support for the Y2K rollover up until the year 2019.

Acknowledged, but until I've seen it I'm cautious...

 

[LCGuy]

Its definately true...i've experimented with my older Macs, and they have no problems recognising any time between 1920 and 2019. The only thing is that after 2019, all our old Macs will roll back over to 1920.