[comp.sys.mac.hardware] mac LC w/ VGA monitor?

djb@mailer.cc.fsu.edu (David Brightbill) (01/24/91)

At Macworld Expo, Scully announced thastandard VGA monitors could be 
plugged into and work with the new LC'  with a special adapter cable.
The folks working the apple booth couldn't give me the specs for the
cable and none of the aftermarket cable vendors at the show had a clue.
Has anyone actually used a VGA with the LC?  Inquiring minds want to know.

brandonl@gold.gvg.tek.com (Brandon Lovested) (01/25/91)

		Macintosh VGA compatibility...

I called up Apple technical support, and they didn't have a clue, either.
They had never heard of such a thing, and assumed I did not know what I was
talking about.  So, I called John Sculley's office.  Naturally, he could not
talk with me, however, I was transferred to PR.  Joy.  PR was busy typing
up Sculley's speech (from MacWorld, presumably), and would get back to me 
the next day.  That was last Friday.  


If you have access to MacWeek, check out the January 22, 1991 issue.  There's
an article on page 6 entitled, 

	"LC suports many VGA monitors,
	 but 'it's a buyer-beware thing.' "

Supposedly, the color correctness, sharpness, or overall "neato appearance" of
VGA monitors is inferior to the Mac Applecolor RGB 13"...according to Apple.

Among those companies whose monitors worked with the LC:
	IBM
	Commodore
	Dell
	Tandy

Do not buy one unless you've tried it out with an LC beforehand!
I do not know how the 512K VRAM chip plays into all of this.  An
assumption would be, if 512k VRAM chip with a VGA monitor, then
256 colors.  I wouldn't bet on it.
Caveat emptor



==============================================================================
BRANDON G. LOVESTED        ::::=:::==::===:====   FOR EVERY VISION,		
Software Design Engineer   ::::=:::==::===:====   THERE IS AN      
Grass Valley Group         ::::=:::==::===:====   EQUAL AND OPPOSITE	
brandonl@gold.gvg.tek.com  ::::=:::==::===:====   REVISION.
==============================================================================

kls30@duts.ccc.amdahl.com (Kent L Shephard) (01/25/91)

In article <1908@gold.gvg.tek.com> brandonl@gold.gvg.tek.com (Brandon Lovested) writes:
>
>		Macintosh VGA compatibility...
>
>I called up Apple technical support, and they didn't have a clue, either.
>They had never heard of such a thing, and assumed I did not know what I was
>talking about.  So, I called John Sculley's office.  Naturally, he could not
>talk with me, however, I was transferred to PR.  Joy.  PR was busy typing
>up Sculley's speech (from MacWorld, presumably), and would get back to me 
>the next day.  That was last Friday.  
>
>
>If you have access to MacWeek, check out the January 22, 1991 issue.  There's
>an article on page 6 entitled, 
>
>	"LC suports many VGA monitors,
>	 but 'it's a buyer-beware thing.' "
>
>Supposedly, the color correctness, sharpness, or overall "neato appearance" of
>VGA monitors is inferior to the Mac Applecolor RGB 13"...according to Apple.
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
But according to Apple, everything is inferior to their products.

>
>Among those companies whose monitors worked with the LC:
>	IBM
>	Commodore
>	Dell
>	Tandy
>
>Do not buy one unless you've tried it out with an LC beforehand!
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

I agree. But don't forget the cables need to be change to be compatible
with a Mac.

>I do not know how the 512K VRAM chip plays into all of this.  An
>assumption would be, if 512k VRAM chip with a VGA monitor, then
>256 colors.  I wouldn't bet on it.
             ~~~~~~~~~~~~~~~~~~~~~~

Well, let's see.  VGA is analog, Mac color video is analog.  Analog
color is limited by the graphics card not the monitor.  I'll bet on it.

THe reason some VGA monitors won't work is that they won't sync to the
same freq. as monitor made especially for a Mac.  Just about all the
analog multiscanning/multifrequency monitors should work.

>Caveat emptor

Always!!!
>
>
>
>==============================================================================
>BRANDON G. LOVESTED        ::::=:::==::===:====   FOR EVERY VISION,		
>Software Design Engineer   ::::=:::==::===:====   THERE IS AN      
>Grass Valley Group         ::::=:::==::===:====   EQUAL AND OPPOSITE	
>brandonl@gold.gvg.tek.com  ::::=:::==::===:====   REVISION.
>==============================================================================


--
/*  -The opinions expressed are my own, not my employers.    */
/*      For I can only express my own opinions.              */
/*                                                           */
/*   Kent L. Shephard  : email - kls30@DUTS.ccc.amdahl.com   */

paryavi@harris.cis.ksu.edu (Saiid Paryavi) (01/26/91)

In article <1991Jan24.145215.20129@mailer.cc.fsu.edu> djb@mailer.cc.fsu.edu (David Brightbill) writes:
>At Macworld Expo, Scully announced thastandard VGA monitors could be 
>plugged into and work with the new LC'  with a special adapter cable.
>The folks working the apple booth couldn't give me the specs for the
>cable and none of the aftermarket cable vendors at the show had a clue.
>Has anyone actually used a VGA with the LC?  Inquiring minds want to know.


Here is the layman's guide to building a cable to connect the LC to standard
VGA monitors:

For this project you will need
	1 male 15 pin D-SUB connector and hood
	1 female 15 pin high density D-SUB connector and hood
	about 10" of cable (at least 5 conductors)

Get out your soldering iron and connect wires and connectors using the
following map:

	VGA side		Mac Side
       15 pin female	      15 pin male
       high density

	  PIN #	    goes to      PIN #
	   1	--------------->  2
	   2	--------------->  5
	   3	--------------->  9
	   13	--------------->  3
       6,7,8,10	--------------->  1,4,6,11,13

On the VGA side, connect pins 6,7,8, and 10 to each other and take only one
wire to the Mac side.  On the Mac side, connect pins 1,4,6,11, and 13 to each
other and solder the wire from the VGA side to one of the pins.

Put the hoods on and if you did everything right, it should work just fine.
It works good for me.

WARNING:  Do this at your own risk.  I am not responsible for the acuracy
of the above and I am definately not responsible for whatever goes wrong.

One last word:  If you do your shopping from Radio Shack, this thing will
probably cost you about $15.  If you shop from a place like Altex
Altex Electronics it cost you about $6.  
--
Saiid Paryavi                      			CIS Department
Internet:  paryavi@harris.cis.ksu.edu			Nichols Hall, KSU
UUCP:      {rutgers, texbell}!ksuvax1!harry!paryavi	Manhattan, KS  66506

rosen@cs.utexas.edu (Eric Carl Rosen) (01/26/91)

What's so special about the LC's graphics card that restricts this "feature"
only to the Mac LC? My vintage 8-bit Apple video card in my Mac II sends out
the same analog signals. Can I build the cable and use it to drive a VGA
monitor with my Macintosh II 8-bit Video Card?

paryavi@harris.cis.ksu.edu (Saiid Paryavi) (01/27/91)

In article <1057@coltexo.cs.utexas.edu> rosen@cs.utexas.edu (Eric Carl Rosen) writes:
>What's so special about the LC's graphics card that restricts this "feature"
>only to the Mac LC? My vintage 8-bit Apple video card in my Mac II sends out
>the same analog signals. Can I build the cable and use it to drive a VGA
>monitor with my Macintosh II 8-bit Video Card?

You can but you might have to make some internal adjustments to the monitor
to get it to sync with the Mac II signals.

--
Saiid Paryavi                      			CIS Department
Internet:  paryavi@harris.cis.ksu.edu			Nichols Hall, KSU
UUCP:      {rutgers, texbell}!ksuvax1!harry!paryavi	Manhattan, KS  66506

gaynor@magnus.ircc.ohio-state.edu (Jim Gaynor) (01/30/91)

In article <1991Jan25.185900.11563@maverick.ksu.ksu.edu> paryavi@harris.cis.ksu.edu (Saiid Paryavi) writes:
>In article <1991Jan24.145215.20129@mailer.cc.fsu.edu> djb@mailer.cc.fsu.edu (David Brightbill) writes:
>>At Macworld Expo, Scully announced that standard VGA monitors could be 
>>plugged into and work with the new LC with a special adapter cable.
>>The folks working the apple booth couldn't give me the specs for the
>>cable and none of the aftermarket cable vendors at the show had a clue.
>>Has anyone actually used a VGA with the LC?  Inquiring minds want to know.
>
>Here is the layman's guide to building a cable to connect the LC to standard
>VGA monitors: 

[layman's guide deleted]

	As an addendum to Saiid's excellent post, I offer this:

	Following are the pinouts for VGA, and for Mac Video.  It has
been said, by Apple, that the Mac LC will drive a VGA monitor,
although major VGA vendors have said that not every monitor will work.
Also note that the Macintosh scan rate is 66.7 hertz, where the more
"standard" VGA scan rate is 60 hertz.

	The January 28th issue of InfoWorld has an excellent article
on the subject.

	I take absolutely no responsibility for the accuracy of this
information, nor will I be responsible if you blow the monitor, the
LC, or yourself to Kingdom Come.

	Insert smileys as necessary.
---
 Jim Gaynor - Systems Analyst 1        + "This is Serious.  He is Lost.
 The Ohio State University ACS-FM-OCES |  We must begin the Search at once."
 gaynor@magnus.ircc.ohio-state.ed      |          -Rabbit, from
 gaynor@agvax2.ag.ohio-state.edu       +          "The House at Pooh Corner"

-Cut Here-------------------------------------------------------------

+-------------------------------+
|      5    4    3    2    1    |
|                               |
 \  10   9    8    7    6      /
  |                           | 
   \  15   14   13   12   11 /
    +-----------------------+

VGA Pin-Out
-----------
1.  Red Video
2.  Green Video
3.  Blue Video
4.  Ground
5.  Ground
6.  Red Ground
7.  Green Ground
8.  Blue Ground
9.  Not Used
10. Ground
11. Synchronize Ground
12. Not Used
13. Horizontal Synchronize
14. Vertical Synchronize
15. Not Used

--------------------------------------------------------------------

+-----------------------------------------------+
|  1     2     3     4     5     6     7     8  |
 \                                             /
  |   9     10    11    12    13    14    15  |
  +-------------------------------------------+

Mac Video Pin-Out
-----------------
1.  Red Ground
2.  Red Video
3.  Synchronize
4.  Synchronize Ground
5.  Green Video
6.  Green Ground
7.  Not Used
8.  Not Used
9.  Blue Video
10. Not Used
11. Not Used
12. Not Used
13. Blue Ground
14. Not used
15. Not Used

-- 
 Jim Gaynor - Systems Analyst 1        + "This is Serious.  He is Lost.
 The Ohio State University ACS-FM-OCES |  We must begin the Search at once."
 gaynor@magnus.ircc.ohio-state.ed      |          -Rabbit, from
 gaynor@agvax2.ag.ohio-state.edu       +          "The House at Pooh Corner"