sorry I just find & make the stuff, you need to ask Hallvard...here's the info he has with the schematic...
compatible with any standard VGA or SVGA monitor (must be able to handle 35.7 KHz horizontal/71.2 Hz vertical) including LCD flatscreen, large monitors, screen projectors etc.
Using the Atari ST with a standard PC (VGA/SVGA) monitor
This text file along with the accompanying illustrations shows you how to
make a cable allowing a standard PC monitor to be used with with your Atari
ST in "ST high" mode (640x400 pixels, black/white).
The two illustrations are supplied in various formats so that they can be
viewed (and printed) on any computer, be it an Atari ST, PC, Mac etc.:
vga_16.gif 16 colour GIF (connection diagram)
vga_2.img Black/white IMG (connection diagram)
resistor.gif 16 colour GIF (trimmer illustration)
res_2.img Black/white IMG (trimmer illustration)
Overview and features
First of all, make sure your PC monitor is able to handle
the Atari ST's frequencies which are as follows:
35.7 KHz horizontal
71.2 Hz vertical
Most modern PC monitors are able to handle this, but please check
with the monitor's user manual before connecting it to the Atari ST.
A couple of common misunderstandings which need to be cleared up:
a) You don't get a bigger desktop (e.g. more room for windows, icons etc.).
The WHOLE picture just gets bigger. Imagine looking at the small
Atari monitor with a magnifying glass.
b) You don't get a colour picture even though the PC monitor is able to
display colour. The Atari ST isn't capable of displaying high-resolution
colour. You can however choose to have the COMPLETE picture shown in a
particular colour if you wish (using variable resistors/trimmers to
fine tune the output).
- Any number of PC monitors can be used (as long as the frequency
specifications are met): large screen, flat LCD displays, projectors etc.
- Audio can be connected to a PC multimedia speaker set, amplifier or
the monitor itself, provided it has a speaker
- If the user wants to, the cable can be made to allow for colour adjustments
meaning that the picture can either be black/white like the Atari ST monitor,
blue, green, yellow, orange, red or anything in between!
- 4 pin (or more) screened cable 2 metres (or any desired length)
- 13 pin DIN (male) connector 1
- 15 pin HD D-sub (female) connector 1
- 47 Ohm resistors (small) 3 (for black/white display)
100 Ohm trimmer resistors (miniature) 3 (for colour adjustable display)
(as small as you can get. They will
have to fit inside the 15 pin connector!)
... and if you want to add audio output (using the monitor's speaker or
external multimedia speakers:
- 1 (or 2) pin screened cable 2 metres (or any desired length)
- 3.5mm stereo jack socket 1 (if using multimedia speakers)
3.5mm stereo jack plug 1 (if using monitor's speaker)
Refer to the connection diagrams while reading the instructions here to
get the full story:
1) Cut the video (and audio if needed) cables to the length(s) you need
and prepare them so they can be soldered to the connectors.
2) Slide the cables through the connector hoods.
It's not much fun realizing that you've forgotten them after having spent
a lot of time making perfect solder connections to the wire ends!
3) Connect the common ground pins of the 15-pin HD D-sub connector together
as shown in the wiring diagram (pins 4,5,6,7,8,10 and 11). I've personally
found it most practical to cut off unused ends of resistors or capacitors
4) Connect pins 4 and 13 (13-pin DIN connector) together.
This is best done with a small wire.
5) a) Solder the three resistors to pins 1,2 and 3 of the 15-pin HD D-sub
connector if you want a fixed black/white display (works fine for
Continue by connecting the common ends together.
b) Solder one end each trimmer resistor to pins 1,2 and 3 of
the 15-pin HD D-sub connector if you want to be able to adjust the
output colour/level of the display (for those of you who like to
Continue by connecting the common ends together.
Solder the unused ends to the wiper pin of each trimmer.
6) Connect the wires of the 13-pin DIN and 15 pin HD D-sub connectors
together as shown in the connection diagram. It might be a good
idea to solder the middle pins of the connectors first as they'll
be harder to reach once other wires have been soldered to the outer
13-pin DIN 15 pin HD D-sub
Pin 9 (Hsync) Pin 13 (Hsync)
Pin 12 (Vsync) Pin 14 (Vsync)
Pin 4/13 (Ground) Pin 4/5/6/7/8/10/11 (Ground)
7) Connect the wire end from pin 11 (13-pin DIN connector) to the common
ends of the resistor (or trimmer) array.
If you want audio output, connect of the wire-end pairs to the 13-pin
DIN connector, and the other to the 3.5mm jack.
The Atari ST audio output is in mono, but since the other end
(speakers in monitor or stand-alone multimedia speakers) will most likely
handle stereo audio you will need to connect the signal wire to both
left and right sides in the jack connector.
Depending on what kind of connector is at the other end you will need
either a jack connector or a jack socket.
9) Check all your connections. If you have someone impartial around,
let him/her check as well.
10) Don't slide the connector hoods over the connectors just yet, but
try it all out first.
You should get the same display as you've always been getting.
You might have to adjust the monitor as the display might have shifted
to one or the other side of the monitor. Nothing to worry about.
If you've chosen to go for the trimmer version of the cable, try adjusting
each trimmer so that you get the colour you want.
11) If everything seems to be working the way it should you can disconnect
the cable (keep in mind that the Atari ST reboots every time that end of
the cable is removed) and finalize the project by sliding the hoods in
place, over the connectors and assembling the 15 pin HD D-sub connector's
Make sure that no wires short circuit. Use insulating tape between wires
and connection pins if necessary.
Hallvard Tangeraas, Oslo, Norway