Re: Daisychaining 5.25 " Drives

[Greg Buchner <apple22@mn.rr.com>]

In article <45059a8c$0$96154$742ec2ed@news.sonic.net>,
 Don Bruder <dakidd@sonic.net> wrote:

> In article <UIidnZ0empu7CpjYnZ2dnUVZ_q2dnZ2d@comcast.com>,
>  "Bill Garber" <willy46pa@comcast.net> wrote:
> 
> > "Mark Percival" <mark@syndicomm.com> wrote in message
> > 1157993693.674164.148300@e3g2000cwe.googlegroups.com">news:1157993693.674164.148300@e3g2000cwe.googlegroups.com...
> > :
> > : Robert O Greenawalt wrote:
> > : > Who knows the limit of daisychaining such drives with one controller
> > card?
> > :
> > : Two drives per card.  I'm not sure which 3rd party controller card Bill
> > : is refering to.
> > :
> > : Mark
> > :
> > : http://www.syndicomm.com/~mark/DM8/
> > 
> > 
> > The Rana drive controller was one that I know of,
> > but, that may have required Rana drives as well,
> > I am not sure exactly. I'd have to research that.
> 
> No research needed - Even with the Rana controller, a standard 
> Apple-issue drive can't "pass along" to anything beyond drive 2 due to 
> the wiring of the connectors/logic on the drive boards (not the 
> controller card, but the drive boards)
> 
> The second connector on the second drive is effectively a "dead end", 
> because the drive-select signal to turn on the second drive is "faked 
> up" in logic by the board of the first drive prior to the signals being 
> passed to the second connnector. Thus the second drive in the chain 
> always sees either "nothing at all" or "They're talking to me". The 
> first drive sees "They're talking to me", and the "faking up" process 
> puts a "nothing at all" signal on the second connector. If the first 
> drive sees a "We're NOT talking to you" signal, it fakes up the "We're 
> talking to you" signal and puts it on the second connector, and the rest 
> of the signals get routed to the second connector for drive 2 to play 
> with.
> 
> So the drives are the critical concept with the Rana controllers - 
> Without "non standard" drives that can pass along a two (or more) bit 
> drive-select signal to the "next drive" connector, it can, like the 
> Apple-issue cards, only talk to two drives max.

It wasn't the drives, it was the controller card.  It's an older 
controller card where each drive plugs into it's own connector, no 
daisy-chaining.  I have one of the cards and a RANA Elite /// (I think) 
to go with it.  I do remember hooking up several drives to one in high 
school, but you could only access the higher drives with RANA's own DOS 
3.3 clone (or modified Apple DOS...never found out what it was.)  And we 
were using 1 RANA Elite I and three Disk ]['s with the card.

Also the local Computerland had a setup with a RANA controller that they 
used for testing Disk ]['s (and other drives) that they fixed.

Greg B.

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