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Falcon - SCSI external cable?

Posted: Mon Jan 14, 2019 9:02 pm
by calimero
is it possible to find SCSI cable for connecting CosmoSex externally to Falcon?

It should be SCSI 2 on Falcon side, and pin header on CosmoSex side.

Is it possible to find such cable?

or: how I can use CosmoSex as external device with Falcon?

I do not need floppy or keyboard/mouse emulation...

Re: Falcon - SCSI external cable?

Posted: Mon Jan 14, 2019 9:12 pm
by Timnaber
There are 2 versions of the original CosmosEx, one for SCSI and one for ACSI.

As far as I know, an ASCI version cannot be used with the Falcon. You need a SCSI specific one for that.

There is currently a new run of 100 units redesigned and waiting to be shipped that can handle either. They should be shipped this month to the people who ordered them already, but in order to get one there is a waiting list.

Re: Falcon - SCSI external cable?

Posted: Mon Jan 14, 2019 9:34 pm
by Greenious
microCosmos is ACSI only, the CosmosEx got both ACSI/SCSI.

The connector is a 50-pin IDC connector, and you should have no problem finding an IDC50 to a standard external connector, such as the 50pin centronic. Like these:

Frm there it should be pretty obvious on how to proceed...

Re: Falcon - SCSI external cable?

Posted: Mon Jan 14, 2019 10:46 pm
by Timnaber
From Jookie's Site

"If your device has both 50-pin SCSI connector and 20-pin ACSI connector, then your device is capable of running on both buses – ACSI and SCSI. But due to small space on PCB, small pin count on Xilinx chip and small amount of logic in that Xilinx chip, the device can’t run in both those modes without reflashing the Xilinx chip. I guess that shouldn’t be a problem, as you won’t switch from ACSI to SCSI and back a couple of times per day (and if you need to do that, you should get another device instead – reflashing of Xilinx is limited to 10’000 times ;) )."

So what I get from this, is that if you have both the 50 pin port and the 20 pin port, you can use either, but a re-flash is necessary when switching. If you only have the 20 pin port, it is ACSI only. This is like the one I own and it is not a micro. It has full Rasberry Pi and metal case with only the 20 pin port, ACSI only.

Re: Falcon - SCSI external cable?

Posted: Tue Jan 15, 2019 3:55 am
by Greenious
You probably have version 1?

Re: Falcon - SCSI external cable?

Posted: Tue Jan 15, 2019 10:01 am
by calimero
First, thanks all for answers.

I do have version 2 of CosmosEx with ASCI and SCSI connector (Pictures in attachment).

I do not have internal SCSI connector in Falcon (like in TT or C-Lab Falcons) so I need cable that on one end have:

1) Falcon SCSI 2, 50 pin, external connector

other end

2) 50-pin IDC connector for Cosmosex.

From link that Greenious post, I would say that I need this:
It looks like adapter that could be plugged in Falcon and provide 50-pin IDC flat cable for Comosex. (I am not sure how can I order this adapter from that link...)

Other problem is that I do not know how SCSI 2 connector on Falcon is called (in Atari manuals they call it "SCSI 2 50 pin" but it is smaller then usual SCSI 2 connectors) so I can not search it efficiently on Google, ebay or aliexpress. (I did not even know that 50pin header like on Cosmosex is called "IDC", thanks Greenious! :) )

Re: Falcon - SCSI external cable?

Posted: Tue Jan 15, 2019 10:45 am
by Greenious
Well, it's kinda messy with early scsi, Apple, zip-drives and some others actually used DB25 (same as the parallell port) as scsi connector, and there were other more or less obvious connectors aswell.

For me, however, the centronics 50 pin connector is SCSI-1, even though it was also commonly used with scsi-2 units aswell.

The falcon connector is what I consider SCSI-2, it's called MD50, the scsi-2 wide version is called MD68.

Wikipedia has a decent article about SCSI connectors and it has this to say:
With the arrival of SCSI-2, the situation was a bit less chaotic. For narrow SCSI, most manufacturers used the MD50, also sometimes referred to as a Micro DB50, High Density or HD50, Half-Pitch or HP50, or MiniHonda

In all honesty, if you go with an IDC50 to MD50 connector or a centronics 50pin doesn't matter, as long as you find the correct cable between that and the falcon. Both work just as good with SCSI-2.

Btw, justto be clear, you will need 2 cables to hook up the CosmosEx to falcon. I am pretty sure you will not find a male MD50 to IDC cable to be able to hook it up with just 1 cable.

Re: Falcon - SCSI external cable?

Posted: Tue Jan 15, 2019 4:25 pm
by Timnaber
Greenious wrote:You probably have version 1?
Yes, I am sure that it is since I waited for the first ones to be made. My first post was because the OP did not specify which version the cable was for. I did not want the wrong path to be taken if it was the original.