What could cause issues with CIA Timing?

Vypr · 11 July 2022, 19:30

I'm still struggling with my ReAmiga 3K.
Todays problem is that the machine was being very erratic. Sometime sit wold work fine but on reboot would either hang at a black screen or wouldn;t detect Zorro cards.
Plugged in DiagROM and found that the CIA tests were giving weird results.
Every test would either pass with flying colours or random failures.
Tick too slow on one pass, then too fast on the next, then fine,

I've tested 3 different sets of working CIA chips so I know they are not bad and the chips test fine in other machines.

alexh · 11 July 2022, 20:31

Wrong crystal fitted somewhere making the wrong clocks going to the CIA chips? TICK SOURCE (J350) jumper setting?

The Diagrom author states this is experimental and might fail.

Quote:

experimental new CIA Test, this should work on NTSC and PAL machines. But it MIGHT give false results, please if you get a fail on both tests send me the timing results to the right and explaining what machine (and TIC jumper setting)

https://www.diagrom.com/index.php/20...-2-1-released/

Leon Besson · 11 July 2022, 20:51

What does the test show on AmigaTestKit? The same? Or different?

Vypr · 11 July 2022, 21:34

DiagROM has two CIA tests, one normal and one experimental. This was on the normal test. Testkit (When I can get the machine to boot) shows the same random results)

alexh · 11 July 2022, 21:54

What did you set J350 to? It should be set to 2-3 (Vsync). If it is set to 1-2 (PSU) then CIA tests will fail.

Vypr · 12 July 2022, 00:48

Quote:

Originally Posted by alexh

What did you set J350 to? It should be set to 2-3 (Vsync). If it is set to 1-2 (PSU) then CIA tests will fail.

It's set to VSYNC, I had replaced the original PSU with an ATX so no TICK signal from the PSU is available anyway.

Daedalus · 12 July 2022, 15:22

Have you checked the EClock signal? IIRC it comes from Gary on the A3000, and should be ~709kHz

hooverphonique · 12 July 2022, 15:46

Quote:

Originally Posted by Daedalus

Have you checked the EClock signal? IIRC it comes from Gary on the A3000, and should be ~7.09kHz

E-clock is 0.7MHz on an A500, so I would be surprised if it's 7kHz on an A3000.

Daedalus · 12 July 2022, 15:49

Quote:

Originally Posted by hooverphonique

E-clock is 0.7MHz on an A500, so I would be surprised if it's 7kHz on an A3000.

Indeed, sorry, it's ~709kHz on all Amigas.

Vypr · 16 July 2022, 22:23

Well, it's decided to behave itself now for some reason event though I've knot done anything. I did measure ECLK on both CIA's and get around 709Khx although it did sometimes spike to 710.2Khz.
Still have to find out why it refuses to boot to SCSI without a CPU card being plugged in and also why after about ten minutes use it loses the ability to detect autoconfig cards.

11 July 2022, 19:30	#1
Vypr Registered User Join Date: Dec 2016 Location: East Kilbride, Scotland Posts: 452	What could cause issues with CIA Timing? I'm still struggling with my ReAmiga 3K. Todays problem is that the machine was being very erratic. Sometime sit wold work fine but on reboot would either hang at a black screen or wouldn;t detect Zorro cards. Plugged in DiagROM and found that the CIA tests were giving weird results. Every test would either pass with flying colours or random failures. Tick too slow on one pass, then too fast on the next, then fine, I've tested 3 different sets of working CIA chips so I know they are not bad and the chips test fine in other machines.

11 July 2022, 21:54	#5
alexh Thalion Webshrine Join Date: Jan 2004 Location: Oxford Posts: 14,448	What did you set J350 to? It should be set to 2-3 (Vsync). If it is set to 1-2 (PSU) then CIA tests will fail. Last edited by alexh; 11 July 2022 at 22:04.

12 July 2022, 15:22	#7
Daedalus Registered User Join Date: Jun 2009 Location: Dublin, then Glasgow Posts: 6,377	Have you checked the EClock signal? IIRC it comes from Gary on the A3000, and should be ~709kHz Last edited by Daedalus; 12 July 2022 at 15:49. Reason: Corrected speed

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11 July 2022, 20:51	#3
Leon Besson Banned Join Date: Feb 2022 Location: Anywhere and everywhere I have a contract Posts: 822	What does the test show on AmigaTestKit? The same? Or different?

11 July 2022, 21:34	#4
Vypr Registered User Join Date: Dec 2016 Location: East Kilbride, Scotland Posts: 452	DiagROM has two CIA tests, one normal and one experimental. This was on the normal test. Testkit (When I can get the machine to boot) shows the same random results)

16 July 2022, 22:23	#10
Vypr Registered User Join Date: Dec 2016 Location: East Kilbride, Scotland Posts: 452	Well, it's decided to behave itself now for some reason event though I've knot done anything. I did measure ECLK on both CIA's and get around 709Khx although it did sometimes spike to 710.2Khz. Still have to find out why it refuses to boot to SCSI without a CPU card being plugged in and also why after about ten minutes use it loses the ability to detect autoconfig cards.

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