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Offline arongoochTopic starter

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Amiga 500 RTC Issues
« on: May 21, 2018, 10:36:29 AM »
Hi all, Recently working on restoring an old A500. Fully recapped the mainboard and the RTC aftermarket 512KB RAM expansion that uses the OKI 6242 RTC chip. Rev 5 motherboard, KS 1.2.

I recently installed a new NiCd 3.6V battery on a set of flyleads to keep it away from anything incase it ever decides to leak. I can set the time via WB preferences and save them. I can fully turn off the machine for say 30 mins and start it back up and sure enough the clock is updated perfectly to the second where it should be.

Problem I am having is if I open utilities/clock program and keep it running the clock refuses to update. So basically when the program loads and shows the correct time the minutes will not tick over, the seconds count up but then randomly on the next minute it might sometimes roll over too it then literally jumps back to the previous minute from when clock is first launched. It cycles over and over without actually counting up with the proper increments in minutes. Hope this makes sense lol

If I close the clock and reopen it, then the clock updates to the proper time and the issue starts over again. One would think, ok perhaps it's a dodgy WB disk or something but ive tried many different copies of Workbench and all seem to cause this same problem and im fairly sure it's not Workbench or clock. Very odd issue to have.

I put this under hardware issues because it's so weird this would be happening as soon as I decided to replace the RTC battery. The quality of my soldering is quite good and I very much doubt it would be a problem here but still open to suggestions. The clock power is also making it to the RTC chip when powered down and is evident with how it keeps time ok when the system is shutdown.

Hoping someone might have some ideas on the cause of this issue. Cheers.
 

Offline Castellen

Re: Amiga 500 RTC Issues
« Reply #1 on: May 21, 2018, 11:03:45 AM »
Get the SysTest binaries from Google Drive:
https://github.com/keirf/Amiga-Stuff

Either use the ADF to write a bootable disk, or run the executable from WB.

Use the real time clock test to see what is read from the M6242 every second.  If you use the reset time/date function you should see it counting up normally from midnight.  If that's not working correctly, then there's probably an issue with one of the clock or data lines to the M6242.

Normally the Amiga reads the hardware RTC once at startup, which it uses to set the time of day counter, which is then incremented by a timer in one of the CIAs.  When something does a system time request, then usually it'll read the time of day counter as opposed to the hardware RTC.

Not sure what happens behind the scenes with the WB1.3 clock prefs, but SysTest is a more reliable way of seeing what the hardware is doing.
 

Offline arongoochTopic starter

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Re: Amiga 500 RTC Issues
« Reply #2 on: September 28, 2018, 07:47:00 AM »
Cheers for the feedback.

I still am having this issue interestingly enough. Recently I download SysTest by KAF and found in this program the time counts and keeps track perfectly fine. I am now suspecting there could be an issue with the WorkBench or Kickstart version I have and am thinking the problem could be in software. I have a Kickstart 3.1 in my A2000 machine so might swap ROMs over and try out WB3.1 just to rule out a possible hardware problem.