Atari Megafile SCSI question

[napabar]

Was there ever a SCSI to ASCI adapter for the Megafile drives, so that you could attach them to other computers with a SCSI interface?

 

I know the ASCI is similar to SCSI, and the internal drives were SCSI themselves, so it seem technically doable.

 

Please note:  I'm aware of the SCSI to ASCI adapters made now that allow you to connect SCSI devices to an Atari ST.  That's not what I'm curious about.  I'm specifically asking about bringing the Megafile forward to a SCSI computer.

[ParanoidLittleMan]

As I know Megafiles were with MFM/RLL drives. Maybe some later with SCSI ?

But those drives are mostly dead now, and very low capacity. Really don't see the point.

Answer would be: if drive is SCSI then you attach it directly to SCSI host. You can use Megafile as power supply.

And:  it's ACSI, not ASCI .

[napabar]

Wether you see a point or not really wasn't in the equation.  They were SCSI drives internally, and yes I do realize you could directly hook them directly up to a new host, but not all ST users would have been comfortable doing that back in the day.  Seems odd that Atari didn't offer Falcon users (for example) an adapter.  And if not Atari, then surely a 3rd party had a solution.  That's what I'm curious about.

[ParanoidLittleMan]

Yes, yes, it is technically possible (SCSI to ACSI adapter). But just because that no one will spend plenty of time and throw away money to develop something what max 10 people will use.

Atari even self abandoned ACSI port - case of Falcon. Because time of IDE drives came. And adding ACSI port to machine would cost at least 10x less than some separated adapter.

You just don't see what has sense to manufacture.

Not to mention lot of mistakes you wrote. "  I'm aware of the SCSI to ASCI adapters "  . It's ACSI to SCSI. Order is not irrelevant.

[ParanoidLittleMan]

Btw. SCSI command set is based on 10 byte commands, ACSI uses old type 6 byte commands (SASI). And all it is in SW. So, some ACSI-SCSI adapter does not convert 6 byte ACSI to 10 byte SCSI, it just make it possible to use them. Or in other words Atari hard disk driver SW what works with basic ACSI works not with modern SCSI. Not even with SCSI in TT or Falcon. Full conversion would be much more complex, and I'm sure that nobody made such adapter. Especially as capacity and commands available with 6 byte commands are limited. Putting ACSI port, with 1GB limit in Falcon in 1992 would be just bad, even if certainly there were numerous users with some ACSI device. But IDE, SCSI and yet ACSI on top of it ? Again, idea is just bad.

[jaybird3rd]

@napabar: Your subsequent responses (now hidden) have been off-putting and rude.  You asked a question and received a perfectly reasonable answer, so why not leave it at that?  Any more attitude and the thread gets locked.

[ParanoidLittleMan]

I gave you answers with explanations, because I'm expert in this area. Of course, you don't care. You have an idea, and now everyone must think how it is good ...

Just continue with that don't care attitude. I stay on my rails. You are already derailed. There is no SCSI-ACSI adapter. People barely using SCSI disks last years, in big part because most of it is dead. Or will be dead soon. 

Ah, and there is no rule that people must answer only what is asked. You had chance to learn something, but ... And hey, you got answer, just not what you wanted, like - sorry that computer World does not work as you imagined.

Off ...  ah, first something about internals of Megafile:  http://www.atari-forum.com/viewtopic.php?t=13720

Where is SCSI there ? Google search gave not something like later Megafile model with internal SCSI . MFM/RLL disk have command set what is rather IDE type.

 

[Colleton]

Well, back in the day I had an external SCSI drive that I put together myself connected to my 520ST.  It consisted of the SCSI drive, an SCSI host board of some type that I can't remember, and an IBM PC external drive case.  Very heavy, but it worked very well.  I don't remember if the host board converted between SCSI and ACSI, but it connected to the ACSI port via cable so it must have done so?

 

Long time ago, sorry.

[ParanoidLittleMan]

Surely board does conversion ACSI to SCSI. There is such in Mega STE and Stacy. But ICD is who made it really good, and that can access over 1 GB. UltraSatan uses ICD protocol too.

 

What is really interesting here is why Atari went on ACSI, what is basically SASI storage connection, protocol. Predecessor of SCSI. Indeed price, not needing plenty of pins were important criteria. 1 GB was plenty in 1985. And it was good even 10 years later.

I think that they intentionally made it not standard - in hope that will self manufacture peripherals like hard disks, printers and other. That was done only partially, and some were better, faster in it. Too bad that Atari self did not manufactured some external hard disk of larger capacity .

[+SoulBuster]

On 12/14/2019 at 6:19 PM, napabar said:

Was there ever a SCSI to ASCI adapter for the Megafile drives, so that you could attach them to other computers with a SCSI interface?

 

I know the ASCI is similar to SCSI, and the internal drives were SCSI themselves, so it seem technically doable.

 

Please note:  I'm aware of the SCSI to ASCI adapters made now that allow you to connect SCSI devices to an Atari ST.  That's not what I'm curious about.  I'm specifically asking about bringing the Megafile forward to a SCSI computer.

Megafile 30s, 60s, SH204 and SH205 I believe all used Winchester drives that required a bridge controller card.  The Controller card in the MF30 and MF60 was Atari's version of the Adaptec Bridge controller card (ACSI in and ST506 data and control cables out). I have never owned the SH204 or SH205, but I think they had Real Adaptec Bridge controller cards in them, but the same result as MF30 and MF60.

Atari did make a true ACSI to SCSI device, the Megafile 44.  The SCSI controller card in the units have two SCSI connectors that you can attach true SCSI devices, like the SyQuest 44 drive.  Two SCSI ports inside with one free allowed installation of a second device.  It is difficult to add a real hard drive because of the space limitations, but it has been done by me and others.

 

Here is a thread on 2 MF44s that I added a SCSI2SD card.  I am able to get 1 gig formatted with two 500 meg partitions with TOS 1.04.  That along with a SyQuest drive in the same unit.  Be aware when using Atari's MF44 controller board limits you to 1 formatted drive per port (2 max), so you are limited to 1 gig on each port.  One of the MF44s I added a SCSI2SD card allows 4 formatted drives.  limiting me to 4 gigs.  This is because someone (not me) had replaced the guts with an ICD AdSCSI, which is not limited like the Atari board.

https://www.exxoshost.co.uk/forum/viewtopic.php?f=18&t=2292&hilit=tim

There is a manufacturer of an ACSI to SCSI Card available for purchase here:

https://shop.inventronik.de/index.php

You can strip out the guts of MF30, MF60, SH204, SH205, or even a MF44, add this device and put real SCSI devices in your Atari Case.  You can even use it to build your own case.

 

Very sweet device!