Path: utzoo!utgpu!utstat!jarvis.csri.toronto.edu!mailrus!purdue!decwrl!labrea!eos!phil
From: phil@eos.UUCP (Phil Stone)
Newsgroups: comp.sys.amiga.tech
Subject: Serial/MIDI project
Summary: Internally mounted, public domain potential
Message-ID: <2550@eos.UUCP>
Date: 7 Feb 89 17:57:42 GMT
Reply-To: phil@eos.UUCP (Phil Stone)
Organization: NASA Ames Research Center, Calif.
Lines: 33

In a posting last week, I asked the greater body of net knowlege if
it knew of any "reserved" use for the two removable panels on the back
of the A2000, directly behind the processor slot.  I have had no replies,
so I'm going to assume that these panels are fair game for the project
I have in mind - a built-in MIDI port and additional serial connectors,
switch selectable.

I've run into a couple of snags on this one.  First, I assume there is a
seperate technical reference manual for the 2000.  What's the quickest way
to get one? Is it in bookstores?  Maybe the answers to the following questions
are in there, but bear with me as I don't have a copy yet.

I was hoping to use the internal serial connector, but it appears to be a
weird copy of the A1000 serial port, and therefore does not bring -12v out
(I could use +-5v for the MIDI interface, but not for the 4066 analog switches
I want to use for port selection - RS232 levels being +-12v on the Amiga, as
far as I can tell).  Anybody know of a good place not too far from this area
in the 2000 to grab -12v?

Finally, how critical are the light brown components that seem to straddle
every line that leaves the A2000 for the outside world?  I would assume they
are EM filters of some kind, no?  If they are critical, where does one find
them - I've never seen anything like them in the electronics catalogs I
peruse.

If I can solve these difficulties, I plan to shoot a PC board for the MIDI
interface (design based on an Electronic Musician schematic) and I will make
the layout and plans available to the net somehow.  Is anybody at all
interested in a cheap, internally mounted MIDI interface?

P.S., please don't tell me to get (or wait for!) a multi-serial board - I'm
looking at cheap solutions here, and I don't need simultaneous use of many
serial devices, just easily switchable access to several outputs.