Amiga 3000 help needed - A3660

General hardware issues and troubleshooting etc

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patracy
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Joined: Mon Jan 25, 2021 3:29 pm

Amiga 3000 help needed - A3660

Post by patracy » Tue Jul 20, 2021 9:47 pm

Anyone in the US able to look at a 3000 for me? I've been battling with trying to get this Amiga going and every time I mix in the A3660 things go south.

3000 desktop with 16mb of ram and 2mb chip. Scsi2sd v.52 with a 64mb sd card. (Workbench set to 1.9gb, then 3 other "drives" set to 18gb) Gotek to load the ADFs. 3.1.4 KS rom. 3.1.4 OS.

I've been able to load 3.1.4 on the amiga and things seem to run just fine like that. But once I put the A3660 things go south in a hurry. I start getting checksum errors on the disc and eventually it corrupts the drive. Some things I've tried include setting maxtransfer rate on the hard drive down to the safe setting. I've tried setting the WB partition down below 2gb. I've tried different SD cards. Heck I started with a 2021 V6 scsi2sd adapter too. The mobo has the termination resistors on it and the cable is only about 5-6" long. Only a single 50 pin connector on both ends. And of course termination is checked in the scsi2sd configuration software. (Yes, all drives have been configured via the windows software on my PC)

I couldn't even get through a 3.1.4 install with the A3660 installed. Without it, it's just fine. Another thing to know is that the card seems to only work in the 5ns setting. Moving the resistor over to 10ns and it won't boot. Speaking with Chucky, he mentioned to try a 60mhz crystal to overclock the 060 and get it to the "right" speed for 5ns. But that wouldn't boot either.

I know the A3660 can be a pain to get working. And I know Chucky mentioned that they typically have issues with the dmac. During all this I replaced the scsi controller chip from the -08 WDC to the AMD version, but that didn't resolve anything. I'm guessing this is a timing issue. I do have a Buddha IDE I could try to use, that would get me away from the dma, but I don't know if that'd address any timing issues going on?

I'd be just as happy sending it to someone in the US to take a look at it and see if they can get it working.

terriblefire
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Re: Amiga 3000 help needed - A3660

Post by terriblefire » Tue Jul 20, 2021 9:56 pm

Can you throw diagrom in there for starters.

Just a sanity check… you have switched the clock jumpers to EXT?
———
"It is not necessarily a supply voltage at no load, but the amount of current it can provide when touched that
indicates how much hurting you shall receive."

patracy
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Re: Amiga 3000 help needed - A3660

Post by patracy » Tue Jul 20, 2021 10:11 pm

I don't have diagrom for a hi/lo rom amiga. Yes, jumpers are moved to get the board to work.

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Re: Amiga 3000 help needed - A3660

Post by terriblefire » Tue Jul 20, 2021 10:25 pm

Pretty much the first thing anyone is going to do is try DiagROM I think you can get them off ebay?
———
"It is not necessarily a supply voltage at no load, but the amount of current it can provide when touched that
indicates how much hurting you shall receive."

patracy
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Re: Amiga 3000 help needed - A3660

Post by patracy » Tue Jul 20, 2021 10:34 pm

I'll reach out to my guy that burned my KS roms and see if he can make up a set for me.

dalek
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Re: Amiga 3000 help needed - A3660

Post by dalek » Wed Jul 21, 2021 12:50 am

I would remove the motherboard resistors and add an external active DB25 terminator. That's what I did on mine to fix my SCSI2SD issues.

SCSI2SD has active termination and mixing active and passive (mobo resistors) is not recommended.

This is the one I used: https://gglabs.us/node/2084

patracy
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Re: Amiga 3000 help needed - A3660

Post by patracy » Wed Jul 21, 2021 12:57 am

I've been down that path to start with as it was recommended it was scsi termination. I've used the "stock" style resistor bus termination (currently in use) along with a external active terminator as well. Neither corrected the checksum errors. Which also never seems to happen with the stock 030. I've also confirmed the diode is still good on the mobo.

dalek
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Re: Amiga 3000 help needed - A3660

Post by dalek » Wed Jul 21, 2021 3:18 am

Just confirming because it wasn't mentioned above - did you remove the motherboard termination resistors when you added the active external terminator?

patracy
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Re: Amiga 3000 help needed - A3660

Post by patracy » Wed Jul 21, 2021 1:30 pm

Yes, I've tried every combo of termination.

Works fine without the A3660.

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Re: Amiga 3000 help needed - A3660

Post by terriblefire » Wed Jul 21, 2021 8:59 pm

patracy wrote:
Wed Jul 21, 2021 1:30 pm
Yes, I've tried every combo of termination.

Works fine without the A3660.
Have you checked your 5V line voltage? The TF4060 boots lovely with a 4.2V 5V rail but the A3660 wont and the PSU connectors are famous for corrosion. Ask @GadgetUK164.

Check the 5V rail at the Amiga somewhere.
———
"It is not necessarily a supply voltage at no load, but the amount of current it can provide when touched that
indicates how much hurting you shall receive."

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