Which is the better scsi card for the A4000?

[Motormouth]

Which is the better scsi card?

The IVS Trumpcard Pro
AMD 53c80 based

or the Dataflyer Plus without the IDE control
AMD 5380 based

I happen to have both scsi cards "lying around"
I wish I had a 4091 for the 4000, or better yet commodore could have put a scsi in the thing.

[alexh]

They are both pretty crap.

Both are Zorro II without DMA and so offer no bandwidth or CPU load advantages over using the A4000's IDE.

Unless you've got a SCSI device you want to use... I'd leave them "lying around" and save electricity.

[AmigaPixel]

They are both pretty crap.

Both are Zorro II without DMA and so offer no bandwidth or CPU load advantages over using the A4000's IDE.

Unless you've got a SCSI device you want to use... I'd leave them "lying around" and save electricity.

I partly disagree, I owned a IVS Trumpcard for my A2000 in 1993, and yes! it was flaky. Although some improvement came after I upgraded the rom.

I switched to The Expansion Systems Data Flyer Plus-SCSI/IDE combo board. It has ran flawlessly for 16 years until recently. However that is an issue with the PSU failing. Correct me if I am wrong but isn't even SCSI I still have a faster throughput than the early IDE channels found on classic Amigas? even with out the DMA, I could be all wet on this, it has been a long time in the classic Amiga hardware era for me. Maybe the later EIDE AtA 66, and ATA100 were better performers

[alexh]

isn't SCSI still faster throughput than the early IDE channels found on classic Amigas? even without the DMA?

I don't think so. Both are PIO and both are 16-bit.

[motrucker]

I wouldn't use ether card in an A4000. You will hate the performance!  Search for a 4091. It's worth the effort.

[Motormouth]

They are both pretty crap.

Both are Zorro II without DMA and so offer no bandwidth or CPU load advantages over using the A4000's IDE.

Unless you've got a SCSI device you want to use... I'd leave them "lying around" and save electricity.

@motrucker  I obviously would prefer a zorro III scsi card, or a scsi on an accelerator, but......

Would a zorro II DMA scsi card work any better?  Would I need to install 16 bit fast ram to get DMA to work as some zorro II DMA cards default to PIO when transfering to 32-bit ram.

I have a GVP scsi card in one of my A2000s that I could switch out.

[LaserBack]

@motrucker  I obviously would prefer a zorro III scsi card, or a scsi on an accelerator, but......

Would a zorro II DMA scsi card work any better?  Would I need to install 16 bit fast ram to get DMA to work as some zorro II DMA cards default to PIO when transfering to 32-bit ram.

I have a GVP scsi card in one of my A2000s that I could switch out.

there is no zorro II scsi card that will work better or faster than the A4000 motherboard IDE

[alexh]

A GVP card with some RAM on it should work use the CPU far less than IDE. But if you have a fast CPU then it will be slower.

[Motormouth]

A GVP card with some RAM on it should work use the CPU far less than IDE. But if you have a fast CPU then it will be slower.

And @Laserback
"there is no zorro II scsi card that will work better or faster than the A4000 motherboard IDE."

Darn, Yes this make sense, and is what I hypothesized.

Thanks, for all your help!!!

[AmigaPixel]

I don't think so. Both are PIO and both are 16-bit.

I see your point, I was thinking SCSI I was 32bit. I just remember SCSI(at least SCSI II and  III) was the preferred hard drive/interface for video editing and animation for a long time. I guess unless you have Zorro 3 SCSI II or III board, sticking to the IDE on an A4000 would be a better choice. That is unless you have SCSI devices that you really need to use.

[AmigaPixel]

I am still a little confused at how and when the Amiga made use of PIO versus DMA, specifically with SCSI and IDE configurations. I remember it was always a big deal that the Amiga had DMA channels

[stevenlcroucher]

Where in the world are you?  I came across a 4091 recently, but as it has not been used in about seventeen years I'm not sure it still works.  You're welcome to it for the cost of postage.

[alexh]

I am still a little confused at how and when the Amiga made use of PIO versus DMA, specifically with SCSI and IDE configurations.

The hardware must be DMA bus master (whereby the SCSI card initiates DMA transfers). The IVS Trumpcard Pro, Dataflyer Plus and Gayle IDE all do not support DMA of any kind.

I remember it was always a big deal that the Amiga had DMA channels

The Amigas DMA channels are between the custom chips and Chip-RAM. Gayle IDE does not have a DMA channel.

[jj]

I am correct in thinking that Zorro II does not offer DMA ?

[tone007]

No.

Well, only to ZII memory.