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Old 30 September 2019, 23:36   #501
Vesuri
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I recently bought a version of this card from AMIGAstore.eu and got it installed in the 0.5MB chip + 1.5MB slow configuration. (Thanks Jope for helping debug my JP2/JP7A brainfart!) Unfortunately neither the OS or the Amiga Test Kit find the RTC on board. SetClock RESET doesn't do the trick. I've measured that the Epson RTC-72421A chip does get 3V from the battery (pins 9 and 18) but other than that I'm not sure where to look at. Any ideas what might cause the RTC not to be found?

I did have the card installed for a moment with an incorrect JP2/JP7A setup. May this have killed the RTC on the card? During the installation process the TOD part of my CIAA also died. Not sure if it's related or not.
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Old 01 October 2019, 20:56   #502
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If resetting the clock does not help, then something may be damaged. Can you see the RTC with keirf systest?
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Old 02 October 2019, 07:30   #503
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Quote:
Originally Posted by Vesuri View Post
I recently bought a version of this card from AMIGAstore.eu and got it installed in the 0.5MB chip + 1.5MB slow configuration. (Thanks Jope for helping debug my JP2/JP7A brainfart!) Unfortunately neither the OS or the Amiga Test Kit find the RTC on board. SetClock RESET doesn't do the trick. I've measured that the Epson RTC-72421A chip does get 3V from the battery (pins 9 and 18) but other than that I'm not sure where to look at. Any ideas what might cause the RTC not to be found?

I did have the card installed for a moment with an incorrect JP2/JP7A setup. May this have killed the RTC on the card? During the installation process the TOD part of my CIAA also died. Not sure if it's related or not.
Is this an A500 or A500+ the card is installed in?

If A500+ there is also a JP9 jumper that tells the system to look for the internal RTC (default) or the external RTC.
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Old 02 October 2019, 17:30   #504
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Quote:
Originally Posted by katarakt View Post
Can you see the RTC with keirf systest?
No, I cannot.

Quote:
Originally Posted by solarmon View Post
Is this an A500 or A500+ the card is installed in?
This is an A500 rev6A.

I used to have a Microbotics M501 512k card with an RTC installed and that one did work but that was prior to the JP2/JP7A changes. I haven't tested it again afterwards - would that require undoing the JP2 modification?

I swapped the CIAs and that moved the TOD problem to CIAB, making clock work again in the OS. However, that didn't affect the RTC not being found.
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Old 02 October 2019, 18:27   #505
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The clock read (_CLKRD) and write (_CLKWR) signals goes to Gary - pins 22 and 23.

Try cleaning the pins and socket of Gary.
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Old 02 October 2019, 23:37   #506
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And, if you can get it to your A500, try the RestartClock tool:

http://thomas-rapp.homepage.t-online...startClock.lha

I suggest the easiest method, is to us a Gotek drive with a Workbench ADF, and another ADF created with Directory Opus and put RestartClock on it.

You can then boot up the Workbench ADF, start a CLI/shell, swap to the other ADF, and run the RestartClock command.
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Old 03 October 2019, 11:53   #507
Vesuri
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And, if you can get it to your A500, try the RestartClock tool

Thanks! Tried it but it didn't do anything. I could write my own code to access the RTC through DC0000-DCFFFF but I doubt this would be that beneficial if the SysTest (for example) won't find the clock at all.
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Old 03 October 2019, 12:41   #508
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So maybe you could check the chip select trace (_XCLKCS) to make sure it is OK and asserted (_XCLKCS is active low).
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Old 03 October 2019, 13:22   #509
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And looking at the schematics/gerbers - there seems to be a jumper to enable the clock? Is this jumper enabled on your board?
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Old 04 October 2019, 00:02   #510
Vesuri
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Quote:
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The clock read (_CLKRD) and write (_CLKWR) signals goes to Gary - pins 22 and 23.
_CLKRD on Gary pin 22 is connected to pin 8 of the RTC chip (through pin 49 of the trapdoor expansion connector). _CLKWR on Gary pin 23 is connected to pin 10 of the RTC chip. As far as I understand these look correct.

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So maybe you could check the chip select trace (_XCLKCS) to make sure it is OK and asserted (_XCLKCS is active low).
If I understand correctly, _XCLKCS is pin 33 on the trapdoor expansion connector and is connected to ground on the motherboard side and to pin 2 of the RTC chip. This seems to be the case in my system.

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And looking at the schematics/gerbers - there seems to be a jumper to enable the clock? Is this jumper enabled on your board?
It is. Here's a photo of the board:



One thing potentially worth mentioning: the system does have a TerribleFire TF530 installed. However, an another RTC did work with it without issues.
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Old 04 October 2019, 08:58   #511
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Have you tried without the TF? And do you still have the other RTC to try out. At least you can rule out your A500 motherboard.

When I had similar RTC issues on my A500+ - it was not found or the clock was not ticking - I tried reflowing the pins of the sockets and components. But this was on a battery damaged A500+

Eventually I replaced the RTC chip itself and it was working and stable since then.

It is a shame the RTC chip on your memory board is not socketed, but you can still replace it if you have the tools and skillset. However, since it is new you might want to consider returning it and getting a replacement, but you should try to rule out your A500 motherboard first.
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Old 04 October 2019, 12:51   #512
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Have you tried without the TF? And do you still have the other RTC to try out. At least you can rule out your A500 motherboard.
The RTC in the old card works still fine (with the TF installed). I haven't tried the new card yet without the TF but I guess it would be surprising if that was the problem since the old one works - especially since this was advertised by AMIGAstore as the perfect companion for the TF

Quote:
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It is a shame the RTC chip on your memory board is not socketed, but you can still replace it if you have the tools and skillset.
Indeed - I don't feel confident replacing it myself with my tools and skillset.

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However, since it is new you might want to consider returning it and getting a replacement, but you should try to rule out your A500 motherboard first.
Yes, I've already contacted AMIGAstore for advice but haven't heard back from them yet.
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Old 08 October 2019, 15:41   #513
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With the board in the Amiga and powered on, what is the voltage at the RTC chip? It needs be within usually 2V to 6V. If it is out of range - i.e. if it is higher than 6V the RTC chip with not work.

I just found this out with one of my memory expansion cards. With the battery removed and card plugged in and powered by the Amiga, the RTC chip was getting 8.1V, due to the 12V source.
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Old 15 November 2019, 21:09   #514
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I had the exact same problem with my RTC not working on the same expansion board, it turned out to be a faulty IC.
By chance I happened to have a RTC in an old memory card that was in a socket. I took that IC and piggy backed it on the suspected faulty RTC on my expansion board, and to my surprise it worked!

So if you have not solved your issue yet, and happen to have a RTC in a socket, try to piggy back it ;-)

*edit* be sure that you have a tight fit when placing the other RTC over the RTC on the expanison, see picture *edit*
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Last edited by CrowStudio; 15 November 2019 at 21:15. Reason: adding picture
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