From: bradford@bu-ast.bu.edu (David Bradford)
Newsgroups: comp.sys.amiga.hardware
Subject: Replies to RGB monitor query
Date: 6 Apr 92 17:51:17 GMT
Reply-To: bradford@bu-ast.bu.edu (David Bradford)
Organization: Boston University Astronomy Department

Below is are edited (to remove long headers and quotations of my articles)
texts of the reponses I have received so far to my query about using a 
Mitsubishi RGB monitor as an Amiga display.  Many thanks to everyone
who responded.  To summarize, the monitor should work fine as a standard
Amiga display, but is not sufficient to be used with a device such as the
FlickerFixer.

David
-----

From hgm@unity.ncsu.edu Thu Apr  2 08:59:55 1992
Date: Thu, 2 Apr 92 08:58:18 -0500
From: hgm@unity.ncsu.edu
To: bradford@bu-ast.bu.edu
Subject: Re: Can I use an RGB monitor as an Amiga display?
Newsgroups: comp.sys.amiga.hardware
Organization: NCSU Computing Center

In article <82979@bu.edu> you write:
>I have a 20" RGB monitor unused at the moment was wondering if it would be 
>possible to use it to get a non-interlaced Amiga display.  I have an Amiga 
>2500 with 1.3 ROM's.  The monitor is a Mitsubishi Model C-3919N.
>
If you are using the amiga in interlace mode, the only way that you'll be
able to get a non-interlaced picture is with some sort of de-interlacer. I
personally prefer Commodore's. However, if the monitor's phosphors are of
the long persistence type, then you can get a nicer picture than you would
get with a regular monitor, unless you are doing a lot of animation work. 

>
>Does anyone know of a device that could drive this thing?  All help will be 
>appreciated.  Please e-mail me and I will summarize and post anything useful 
>or interesting I receive.  Thanks.

It looks to me that the base amiga will drive this monitor just fine. 

Something to try:

Get a BNC to RCA (audio connector) cable, and hook the green gun to a
composite video source (like the video out on your amiga). Do you get a
picture. Groovy.

Wiring the cable is pretty easy. You simply need to tie each of the guns on
the monitor to the 3 RGB analog outputs, tie sync to the sync line, or the
ground side of the green gun. 

To see if it will work with commodore's de-interlacer, try hooking the
monitor up to a standard VGA system. Commodore's de-interlacer provides the
same signal, with the same pinouts. 

--hal
-- 
hgm@ccvr1.cc.ncsu.edu	"I'm not cheap, you understand,
			 I'm just a cut-rate person in a low budget land."
			 		Kinks

From cendata!vserbe@uunet.UU.NET Thu Apr  2 13:49:27 1992
Date: Thu, 2 Apr 92 04:57:55 CST
From: cendata!cendata!vserbe@uunet.UU.NET (Vic Serbe)

You can use the A520 composite RGB converter. It costs 35-50 bucks.
You can actually drive the monitor right now with the "video" output
on the back of your machine (next to the audio outputs), but it will
be monochrome only. Only the A1000 has color composite "video" output
on the back (I know, pretty stupid). Also, you want to use the 3:4
aspect ratio. Interlace is 640x400 which is approximately 4:3 (I think
the monitor's manual has the values swapped). 640x200 still uses pixels
that are about 4:3, but only draws half as many lines vertically. All
you need to do is wire a standard RCA (phono) plug to that BNC connector.
Just make sure the "shell" on the phono plug is ground on the BNC end.
Also, use shielded cable. It'll help you avoid monitor "swim".


Vic Serbe		"able was i ere i saw elba"
Central Data scsiSupport | PH# (800) 482-0315 x237 |
vic@cd.com		 |     (217) 359-8010 x237 |
uunet!cendata!vic	 | FAX (217) 359-6904	   |


From SEB@lns61.tn.cornell.edu Thu Apr  2 15:19:13 1992
From: "Selden E. Ball, Jr." <SEB@lns61.tn.cornell.edu>

David,

In principle, it sounds to me like your Mitsubishi monitor should work
with an Amiga. The frequency specs sound ok.

One problem with many monitors is that the SYNC lines
have an input impedance of 75 ohms. Amigas assume that this means
that an external genlock is connected. You have to provide an adaptor
that buffers the sync lines.

I would suggest that you contact Redmund Cable. They make all sorts
of adaptor cables for the Amiga. Connecting various industrial monitors
is something that they have done many times. Unfortunately I don't have
their address and phone number. They frequently advertise in most of
the Amiga magazines.

I hope this helps.

Selden Ball
seb@lns61.tn.cornell.edu

From chuckg@cruzio.santa-cruz.ca.us Fri Apr  3 13:12:46 1992
Date: Fri, 3 Apr 92 8:13:30 PST
From: chuckg@cruzio.santa-cruz.ca.us (Charles Gallagher)

I am currently useing a 15" Mitsubishi FL/HL6615K with my 3000.

I had to hack a cable and screw arround with the preferences, but the result
is a super monitor.

The Amiga apparently does not mix any sync with green, so I have 5 cables to
the monitor.

Please feel free to contact me if you have any more questions.


-- 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
~  Chuck Gallagher      chuckg@cruzio.santa-cruz.ca.us       (408) 464-2180  ~
~  Visualization Systems        3835 Moana Way         Santa Cruz, CA 95062  ~
~                                                                            ~
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

From tomb@lsid.hp.com Mon Apr  6 12:58:38 1992
Date: Mon, 6 Apr 92 08:57:43 pst
From: Tom Bruhns <tomb@lsid.hp.com>

David,

I have a monitor with similar characteristics.  If it won't go to
31.5kHz horizontal, you won't be able to use it with 31.5kHz video:
flicker fixer, or display enhancer.  However, it still may make a
wonderful interlaced display at the standard 15.75kHz rate.  Oh,
you can for sure also use it with a non-interlaced workbench (640x200).
But I assume that wasn't what you meant.  --  You just hook the
R, G, B and Sync lines up to the appropriate pins on the 23 pin db
connector on the Amiga.  I found with my monitor that the sync line
had to be unterminated to get enough sync signal, but that may be a
monitor anomaly.

Cheers,
Tom

-----
--
David Bradford           Internet: bradford@bu-ast.bu.edu
Systems Manager          BITnet:   bradford@buasta
Astronomy Department     NSI/DECnet: buasta::bradford
Boston University        Phone:    (617)353-4884   	FAX: (617)353-5704
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