Path: utzoo!utgpu!utstat!jarvis.csri.toronto.edu!mailrus!csd4.milw.wisc.edu!bionet!ames!killer!elg
From: elg@killer.Dallas.TX.US (Eric Green)
Newsgroups: comp.sys.amiga.tech
Subject: Re: Need advice on hardware projects
Message-ID: <7916@killer.Dallas.TX.US>
Date: 22 Apr 89 18:36:24 GMT
References: <9891@netnews.upenn.edu> <6622@cbmvax.UUCP>
Organization: The Unix(R) Connection, Dallas, Texas
Lines: 72

In message <6622@cbmvax.UUCP>, daveh@cbmvax.UUCP (Dave Haynie) says:
$in article <9891@netnews.upenn.edu>, ranjit@eniac.seas.upenn.edu (Ranjit Bhatnagar) says:
$> I'm considering building one or more of the following hardware
$> projects, for kicks and to save some dough.  
$That's cool, and really shouldn't be any major design problem.

However, there may be some construction problems. I remember reading
about noise nightmares with wire-wrapping on ancient S-100 busses
using 2mhz 8080s, and similiarly with memory boards, so will
definitely have to be a pc board. Do you have the facilities? If not,
prototyping services can get expensive real quick (i.e., forget about
saving some dough).

$> 	* A zorro-II card cage for the 1000 
$> 		I figure I need a case, a real smooth power supply,
$> 		and about a zillion bus drivers.  

This would be a VERY good project. Current Zorro-II card cages only
have 2 or 3 slots, and are somewhat pricy (i.e., >$175). I suspect
that most of that's because of the power supply and case -- a
commercial outfit cannot rely on cheap surplus power supplies and
cases. You can. 
    One nice thing is that, if you design it right, it can also be
used with the Amiga 500. Just make sure that the "fingers" stick out
far enough so that components don't bump up against the "ledge" on an
Amiga 500 (means you'll see a little open air between the box and the
A-1000, but that should be no big deal). 
   My purchasing plans for the future include a hard disk controller,
a RAM card, and a multi-serial I/O card. I have an old IBM power
supply to supply juice to it all.  Current 2-slot A-500 boxes are
simply too small, and contain a power supply and case that I do not
need.
   I just asked my brother what it'd cost to get quantity three from a
prototyping service. He said it'd be probably about $40/board plus a
setup charge of maybe $100. Going quantity 100 would probably bring
the blank PCB cost below $10, but the question of what to do with the
other 99 arises ;-). 


$> And where can I get a QUIET fan to put in the box?

I always wonder about people who insist on QUIET fans. The first time
I turned on an Amiga 1000, I almost freaked, because I didn't hear the
vigorous "whoosh" of most AT-clone fans. That "whoosh" is reassuring
to me, because it means that my fan is still running and my equipment
is still keeping cool. 

$> 	* A 32-bit memory card for the Ronin Hurricane 1000.
$> 		I have no idea how complex a project this is - there must
$> 		be SOME reason why an unpopulated 32-bit card costs
$> 		over 500 bucks, but I'd love to avoid paying that.

The costs of low quantities extend beyond the higher cost of the PC
boards (which in itself is quite significant). It takes just as many
people to ship out a hundred per month as it takes to ship out a
thousand per month, and I suspect that Ronin is shipping in relatively
low quantities. Your development staff has to be paid whether you're
shipping hundreds or thousands, unless it's a one-man operation...

$> 		Would a hand-drawn pc-board be far too noisy for
$> 		such an application anyway?  (Well, drawn in MacDraw
$Nothing's inherently wrong with hand-drawn boards, if you're using a
$CAD program of some kind, though you may have to manually follow 
$design rules to get a reproducable board.  

You may want to get PCLO or some other such program. Drawing up PC
boards entirely by hand is, at least for me, infuriating. 

--
|    // Eric Lee Green              P.O. Box 92191, Lafayette, LA 70509     |
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| \X/            Amiga.  The homestation for the blessed of us.             |