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Amiga computer related discussion => Amiga Marketplace => Topic started by: Dragster on March 02, 2009, 06:44:20 PM

Title: WTB: DMAC 04 for Amiga 3000
Post by: Dragster on March 02, 2009, 06:44:20 PM
Hi,

I'm looking for the DMAC-04 (rev 04) chip for my Amiga 3000 which I recently got off ebay. I already have a SuperBuster 11 and Ramsey 7, so she only needs the DMAC rev. 04 now. I know these chips are hard to find and sometimes they can grab big bucks on ebay, but I'm counting on a fellow amigan to sell me one for a reasonable price, my Amiga 3000 will appreciate it :-)

PM me please.

Thank you!
Title: Re: WTB: DMAC 04 for Amiga 3000
Post by: matthey on March 02, 2009, 11:57:36 PM
Be careful. Some accelerators have problems with the Ramsey 7 DMAC 4 combo. The motherboard SCSI becomes flakey (read checksum errors) at least with newer ROMs (3.1 in my case). No accelerator is fine with the combo though. The SCSI was about 1Mb/sec faster with the newer combo. I went back to old chip versions in my 3000T because of the problem. I kept the Buster 11. It's a great upgrade for a 3000. My 3000T is very reliable with out the combo. I would hate for you to spend $100 and be disappointed. There is probably more bang for the buck elsewhere IMHO.
Title: Re: WTB: DMAC 04 for Amiga 3000
Post by: Dragster on March 03, 2009, 12:36:40 AM
Heya Matthey

Quote

Be careful. Some accelerators have problems with the Ramsey 7 DMAC 4 combo. The motherboard SCSI becomes flakey (read checksum errors) at least with newer ROMs (3.1 in my case).



Well, never heard of this but I have the newer scsi chip (rev 08-2005) which hopefully will work reliable after the upgrade, I don't know for sure though.

Quote


 No accelerator is fine with the combo though.



Absolutely none? I'm planning on installing a rev 3.1 A3640 in it...

Quote

The SCSI was about 1Mb/sec faster with the newer combo.


A good reason to upgrade then.

Quote

 I went back to old chip versions in my 3000T because of the problem. I kept the Buster 11. It's a great upgrade for a 3000.



Yeah, I have the buster now... (rev 11).

Quote

My 3000T is very reliable with out the combo. I would hate for you to spend $100 and be disappointed. There is probably more bang for the buck elsewhere IMHO.


I see... well, I don't plan to spend that much on it, hopefully I can find it cheaper from someone who doesn't want to take advantage of me (or abybody else) selling it for that or much more.

I guss there are good and bad points on doing this upgrade, but there are more good reasons to do this upgrade than the good ones for not doing it from what I've read.

Thank you,

Dragster
Title: Re: WTB: DMAC 04 for Amiga 3000
Post by: matthey on March 03, 2009, 01:38:11 AM
I have the newer SCSI chip in the 3000T also. I still got the errors. I think the 3640 may work ok with the DMAC 4 & Ramsey 7. A CSMK3 didn't and a PP&S Mercury I heard exhibited similar symptoms. They both have memory on board. I thought it was the motherboard SCSI using the accelerator memory buffers and tried changing the RDB MASK to only use motherboard memory but I didn't have any success. I could have disabled the motherboard SCSI but then the only improvement I saw was SCSI speed. It may speed up ram as well but the accelerators memory is faster and used first if it has it. If anyone has more info on my problem, I would like to hear about it. Good luck finding a rare DMAC 4, Dragster.
Title: Re: WTB: DMAC 04 for Amiga 3000
Post by: Dragster on March 03, 2009, 02:36:14 AM
@matthey

Thanks for the wishes, yeah I know it's an almost-impossible task but I'm sure there will be sooner or later someone out there willing to help :-)

Cheers
Title: Re: WTB: DMAC 04 for Amiga 3000
Post by: save2600 on March 03, 2009, 02:52:21 AM
@ Dragster:

PM sent.  
Title: Re: WTB: DMAC 04 for Amiga 3000
Post by: Dragster on March 04, 2009, 05:29:51 PM
Hi, a posibility came to get one with Save2600 but unfortunately it turned out to be a rev 02-- So... still looking for the rev 04 DMAC.

Cheers,

Dragster
Title: Re: WTB: DMAC 04 for Amiga 3000
Post by: Dragster on March 05, 2009, 07:36:29 PM
 :bump:
Title: Re: WTB: DMAC 04 for Amiga 3000
Post by: Dragster on March 09, 2009, 11:31:44 PM
 :bump:
Title: Re: WTB: DMAC 04 for Amiga 3000
Post by: Dragster on March 13, 2009, 04:45:53 PM
 :bump:
Title: Re: WTB: DMAC 04 for Amiga 3000
Post by: Dragster on March 17, 2009, 05:33:16 PM
Another :bump:
Title: Re: WTB: DMAC 04 for Amiga 3000
Post by: Dragster on March 23, 2009, 06:40:23 AM
One more :bump: