Re: Apple Drive III cable

[cps@access.digex.net (Chris Smolinski)]

In article <3171F5CA.3FA@ais.net>, Jon O'Brien <jobrien@ais.net> wrote:

> I'm curious as to how the computer can tell the difference between the
internal .d1 and an 
> external .d2 (or .d3 for that matter) when the ribbon cable connecting
the port goes strait 
> through for the internal drive.  If it is indeed a pass-through
connection then the only reason 
> that the port on the internal drive's analog board does not work is that
it was intentionally 
> disabled (i.e. jumper setting or a cut on the board).  This would make
adding a 26-pin connector 
> or a 26-pin -> DB25 adapter for the external drive simple.
> 
> If anyone thinks (or knows) that this is a bad idea as I naturally do
not want to fry what is 
> otherwise working equipment!
> 
> Jon

I'll have to dig up my Apple /// notes for full information, but the drive
ribbon cables daisy chain. There are four drive select signals, and each
drive shifts them over by one, so the drive automatically are assigned
numbers. I believe there is a slight difference between the internal drive
wiring and the external drives, since the internal is always .D1. Note
that you can use /// drives on a ][, and vice-versa, with appropriate
cabling. I'll try to dig out all my /// stuff after I move (and can
finally set my Apple collection back up again)

Chris

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