Conference hydra::amiga_v1

638.0. "ST506 Drive/Cont. for Escort2" by LEDS::ACCIARDI () Fri Aug 07 1987 15:14

A non-full-time DEC employee friend asked me to post this in the Amiga Notes
file, in case there are any Escort2 owners out there.


>Ed,
>Here's the scoop on Expansion Technologies.  Just in case there are
>other Escort 2 owners out there like myself looking for a compatible
>disk controller to plug into that second slot, here's an option!
>They have an ST506 I/F card available Sept. 1 for their Escort 2!
>I couldn't find anybody who had a disk controller card for the extra 
>slot in my Escort 2, so I called them last night just for info and
>ended up ordering the following.
>A guy named Rich told me about a special pre-release-to-distributors
>deal they have for the first 100 Escort owners who call.  For $799. you
>get an ST506 I/F board which plugs into the second slot of the Escort 2,
>a 20Mbyte 60microsecond drive, and all the cables, cabinet, and power
>supply needed to make it work.  For $1099. you can get a 40Mbyte 40micro-
>second drive instead of the 20Mb.  He said it's all working today and
>they are gearing up production now.  The controller will handle 2 drives,
>transfers at 5 Mbits/sec into a 'track buffer' which then emptys into the
>Amiga at 'pseudoDMA' rates.  Don't ask me to explain.  The number, for
>those who are bound to ask, 415-656-2890 in California.
>S'later

I have no connection with the makers of the Escort2, blah blah...

    I don't see the big deal hear; for less than $799 on the street you
    can get a C Ltd., etc., drive  wtih a standalone interface, and still
    have your extra slot - providing your box passes the buss, or else
    you opt for C Ltd.s $40 pass the buss widget.

    Also, I have trouble taking seriously claims of a "40 microsecond"
    or "60 microsecond" drive.  Milliseconds I would believe.
        John Sauter

Re: .1

I guess the big deal is you get to expand using your expansion box rather
than another buss add on.

I recently got a copy of Commodore's official hardware schematics and
expansion documentation for the Amiga 1000.  A good part of the manual
is taken by the design of a multi-slot expansion box designed by Commodore
Amiga but never marketed.  The docs clearly state that it is there is a
problem with having more than one buss add on on the Amiga 1000.  One of
the goals of the Commodore-Amiga expansion box was to try and have very tight
tolerances of the design of the expansion so you could use to connect to
expansion boxes to get 10 slots instead of 5 or whatever.

By the way this is old news.  The document (and thus the Zorro standard)
dates from early (I think February) 1986.

So the conclusion is: It is possible to have to up to two buss add ons
it you are very careful, but it is pushing tolerances.  It is better to
expand inside of an expansion box, if possible.