ACSI/DMA to SCSI Adapter

[DominoTree]

Ha, of course someone already made basically the same thing I was doing

[alienkidmj12]

wow, i'm very interested in this, wanted to get rascsi up and running in a mste i think this might be the solution

[Bikerbob]

So this has been done by tOri. He has remade a bunch of the ADscsi ICD interfaces. http://atari.myftp.org/index.html

I have tried to take those and convert them for external use.

I have converted the micro and the MegaSTE.

These have yet to work with any SCSI alternative devices. The original tOri devices work on real HDD. So something in my conversion to external connection is messing it up.

If your good with schematics can you review my work please?
These are the original MegaSTE internal and my external. Also my version of the ICD micro. The only difference between the two is the megaSTE version does generate parity which many devices want. The original micro does not. In my version of the micro I have also removed the boot delay circuit.

[tOriman]

Hi Bikerbob,

I got a Mega STe from a friend for testing purposes and it has BlueSCSI F1 inside. Everything works fine with the internal Micro STe adapter - I tested two pieces made for friends, so the BlueSCSI v2 has some unknown Micro interface issue....

@DominoTree your diagram look very similar to this OLDie published on my site: http://reversing.pl/atari16bit/a16scsi/a16scsi.html. This interface is OK but there is 1GB limit and no ICD extended commands, A bit useless in this time. Your diagram hasn't some required parts like pull-up resistors on SCSI connector side.

Last days I made modernized version of ICD AdSCSI Plus interface with czietz's Initiator patch. I'll assemble and check it in near future and publish new documentation on my www.

tOri

[Bikerbob]

TOri can you take a moment and really look over my conversion?? I feel it must be something I've changed since you have had so much success with your internal devices.

James

[tOriman]

@Bikerbob

Gimme some time. I'll check it. Is it this file -> Schematic_megaSTE-adapt_2024-06-27.pdf ? Your last one?

tOri

[Bikerbob]

@Bikerbob

Gimme some time. I'll check it. Is it this file -> Schematic_megaSTE-adapt_2024-06-27.pdf ? Your last one?

tOri

yes .. the two dated files are my last revisions of the external conversions.

James

[tOriman]

Hi @Bikerbob !

I checked your conversion. It is OK. It looks like BlueSCSI version 1 is working, and there is a problem in version 2.
I don't have BlueSCSI v2. ANyway - If Harddisk works well with this interface - other devices should also work.
I'm betting on a BlueSCSI v2 problem in this hardware configuration. I don't know how to help you.

tOri

[Bikerbob]

Hi @Bikerbob !

I checked your conversion. It is OK. It looks like BlueSCSI version 1 is working, and there is a problem in version 2.
I don't have BlueSCSI v2. ANyway - If Harddisk works well with this interface - other devices should also work.
I'm betting on a BlueSCSI v2 problem in this hardware configuration. I don't know how to help you.

tOri

You looked at my MegaSTE external? did you look at my micro as well? Hmmm.. interesting.. So my wiring seems to be ok.

I wondered about my programming of the GALs but the unaltered megaSTE works so I have no joy there.

As for working - the ones that I converted to external - do not work at all - with anything. I am plugging the devices directly into the DB19 port.. so no cable length there.. and for bluescsi etc.. they plug directly in the back of that. A HDD would have a 12" ribbon cable. but that cable works fine on the internal interface, so I dont think its cabling.

James

[frank.lukas]

... a Mega STE internal Hostadapter must serve the DMA Out port like the original MegaSTE/Stacy Hostadapter do.

Remove the internal Hostadapter and put Jumper for D0-D7 on the MSTE Mainboard ...

tOri Advantage ICD Hostadapter in my MegaSTE ...
https://forum.atari-home.de/index.php/t ... #msg268739