[Coco] collecting info for converter

Gene Heskett gene.heskett at verizon.net
Wed Feb 8 17:27:33 EST 2006

On Wednesday 08 February 2006 14:44, Sylvain Rousseau wrote:
>Hello Roy,
>This is the pinout for the video connector of an Amiga
>500/600/1000/1200/2000/3000 and 4000.  I got it at
>and the connector is a ?/%$?# DB23, yes a DB23 male and I don't know
> where I can find one.  I can hack my A2000 to add it an other
> connector to test the RGB to VGA
>adapter and I'm willing to do it but I prefer to use a DB23 if I can
> find one.
>Pin     Name            Description
>1       /XCLK           Extern Clock
>2       /XCLKEN         Extern Clock Enable (47 Ohm)
>3       RED             Analog Red (75 Ohm)
>4       GREEN   Analog Green (75 Ohm)
>5       BLUE            Analog Blue (75 Ohm)
>6       DI              Digital Intensity (47 Ohm)
>7       DR              Digital Red (47 Ohm)
>8       DG              Digital Green (47 Ohm)
>9       DB              Digital Blue (47 Ohm)
>10      /CSYNC  Composite Sync (47 Ohm)
>11      /HSYNC  Horizontal Sync (47 Ohm)
>12      /VSYNC  Vertical Sync (47 Ohm)
>13      GNDRTN  Digital Ground (for /XCLKEN) Don"t connect with pin
> 16-20. 14      /PIXELSW        Genlock overlay (47 Ohm)
>15      /C1             Clock out (47 Ohm)
>16      GND             Video Ground for RED Analog (useful to know
> because some TVs need specific grounds for specific colors when using
> SCART/PERITEL SECAM video signal)
>17      GND             Video Ground for GREEN Analog
>18      GND             Video Ground for BLUE Analog
>19      GND             Video Ground for CHV SYNC
>20      GND             Video Ground
>21*     -12V            -12 Volts DC (10 mA max) (A500/A600/A1200)
>21*     -5V             -5 Volts DC (10 mA max)
> (A1000/A2000/A3000/A4000) 22      +12V            +12 Volts DC (100
> mA max)
>23      +5V             +5 Volts DC (100 mA max)

Let me jump in here and add that the h&V sync signals on this port, will 
if terminated, cause the agnus to shut down to protect its output 
drivers.  Thats why nearly every cable ever made had a chip, sometimes 
even a cmos chip, buried in the hood of that db25 connector, whose job 
it was to buffer those 2 or 3 signals.

I was amazed to find this when I bought my first 2000 used off an amiga 
mailing list and found that it came with a commie genlock board in it 
because it could drive a monitor.  An email to Dave Haney confirmed my 
agnus shutdown deduction FWIW.  I assume the seller had put it in when 
he found he couldn't drive a normal monitor (some non commie model I 
suppose) with the regular db25 cable attached.  So I made one up using 
a TTL chip buffer/invertor and put it into mine, and ran w/o the 
genlock card until I finally bought a picasso-II, which is still in it, 
set to run at 1600x1200 24 bit color IIRC.  The chip runs from power 
available on pin 23.

>At 14:25 2006-02-08, RJRTTY at aol.com wrote:
>>In a message dated 2/8/06 1:11:02 P.M. Eastern  Standard Time,
>>srousseau at comlab.com writes:
>> >Hello Roy,
>> >
>> >I  should be on the list to buy you a
>> > RGB to VGA adapter for my  Coco.
>> >
>> >Also, I have an Amiga 2000.  When I
>> > got the  adapter I am willing to try it
>> >with the Amiga and give you some
>> >feedback on the mailing list.
>> >
>> >Sylvain
>>Thanks for the  offer.    You are on the
>>list at about 3 weeks down.
>>I  would need to know the type of connector
>>and pinout configuration the Amiga  uses.
>>Coco mailing list
>>Coco at maltedmedia.com

Cheers, Gene
People having trouble with vz bouncing email to me should add the word
'online' between the 'verizon', and the dot which bypasses vz's
stupid bounce rules.  I do use spamassassin too. :-)
Yahoo.com and AOL/TW attorneys please note, additions to the above
message by Gene Heskett are:
Copyright 2006 by Maurice Eugene Heskett, all rights reserved.

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