----------------------------------------------------------------- | CONVERSION BETWEEN SPACE DUEL AND GRAVITAR | ----------------------------------------------------------------- COPYRIGHT 2000 REVISION NUMBER: 1.1 REVISION DATE: 25 October 2000 CREATED BY: John Lee and amended by Tom McClintock PART I: Conversion of A Space Duel Control Panel to Gravitar PART II: Gravitar Control Panel In A Space Duel Cabinet PART III: Other Helpful Space Duel/Gravitar Information STANDARD DISCLAIMER: -------------------- REMEMBER, NO WARRANTEES, EXPRESS OR IMPLIED, ARE GIVEN. USE THIS INFORMATION AT YOUR OWN RISK. I AM NOT RESPONSIBLE FOR ANY DAMAGES THAT MAY OCCUR TO YOUR PERSON OR PROPERTY. ----------------------------------------------------------------------- PART I. CONVERSION OF A SPACE DUEL CONTROL PANEL TO GRAVITAR by: Tom McClintock ----------------------------------------------------------- GENERAL OVERVIEW: ----------------- Having an Atari Space Duel cabinet and an extra Atari Gravitar PCB, I proceeded to come up with a simple and non-invasive way to play Gravitar in my Space Duel cabinet. Since Space Duel and Gravitar share almost identical control panel layouts (aside from the fact that Space Duel has two sets of controls while Gravitar has only one), Gravitar can be easily incorporated into the cabinet with a small control panel adapter harness. The Space Duel cabinet wiring harness is pin compatible with a Gravitar PCB, but the Gravitar PCB looks for player inputs on different pins than what the Space Duel control panel provides. So, a small conversion harness must be inserted between the Space Duel control panel and the Space Duel wiring harness to send the correct signals to the Gravitar PCB. The Gravitar game PCB requires no alterations with this conversion. I chose the Player 2 controls on the Space Duel panel to act as the controls for Gravitar as they get used less frequently. If you are so inclined, it is just as easy to map the Player 1 controls to play Gravitar. The Start Switch becomes "Player 1 Start" and the Select Switch becomes "Player 2 Start". The "Shields" button also acts as the Tractor button - exactly as the original Gravitar control panel layout. The wires on the Space Duel control panel harness that are not explicitly listed are not connected. INGREDIENTS: ------------ 1 - Working Gravitar Board 1 - AMP 24-pin Miniature Rectangular Pin Housing (AMP# 1-640515-0) 1 - AMP 24-pin Miniature Rectangular Socket Housing (AMP# 1-640525-0) 13 - AMP MR Live Split pins (or equivalent) 13 - AMP MR Standard Socket pins (or equivalent) 13 - Three-inch segments of 20 gauge insulated wire [note: please check the AMP web site for distributors www.amp.com ] HARNESS CONSTRUCTION: --------------------- <------------------------------------------> Space Duel to Gravitar Conversion Harness using Space Duel Player 2 controls Space Duel CP Space Duel Harness pin 1 to pin 11 pin 2 to pin 9 pin 3 to pin 3 pin 4 to pin 14 pin 5 to pin 5 pin 6 to pin 13 pin 7 to pin 7 pin 13 to pin 6 pin 14 to pin 4 pin 21 to pin 21 pin 22 to pin 22 pin 23 to pin 23 pin 24 to pin 24 <------------------------------------------> TROUBLESHOOTING: ---------------- - Check the continuity on each harness wire before inserting it into the AMP connector. This is obvious, but sometimes overlooked. - Before you insert each wire into its respective AMP connector, carefully note the male/female orientation of the pre-existing Space Duel harness(es). If a button is not working or is operating a different feature, then check proper pin-to-pin connections. - Try to make the conversion harness as short as possible to eliminate any unnecessary bending of the Space Duel cabinet harness. - The self test routines for a Gravitar PCB are the same as for a Space Duel PCB with one difference. While Space Duel utilizes the SLAM switch to step through the self test screens, Gravitar uses the aux coin switch mounted next to the coin counter. ----------------------------------------------------------------------- PART II. GRAVITAR CONTROL PANEL IN A SPACE DUEL CABINET: by John Lee (jhlee@hac2arpa.hac.com) ----------------------------------------------------------- The following describes how to connect an Atari Gravitar control panel to the Atari Space Duel cabinet harness. Both the Gravitar control panel and game PCB are virtual drop-in substitutes into the Space Duel cabinet. However, while the Gravitar panel has a 12-pin Molex-type connector, Space Duel uses a 24-pin AMP connector [# 1-640515-0]. In my own conversion, I made a small adapter that plugs in between the Gravitar control panel and the Space Duel harness. With this adapter, no alterations are made to the harness or control panels and it is easy to switch between the games. The Gravitar game PCB requires no alterations. The wires on the Space Duel harness that are not explicitly listed are not connected. The pin numbers given are for connector J24/P24 on both game's schematics (the connector at the control panel.) For your reference, the wire colors are included below. HARNESS CONSTRUCTION: --------------------- <------------------------------------------> Space Duel to Gravitar Conversion Harness using a Gravitar Control Panel Gravitar CP Space Duel Harness pin 1 to pin 13 pin 2 to pin 3 pin 3 to pin 7 pin 4 to pin 9 pin 5 to pin 14 pin 6 to pin 5 pin 7 to pin 11 pin 8 to pin 6 pin 9 to pin 4 pin 10 to pin 21 pin 11 to pin 23 pin 12 to pin 24 <------------------------------------------> ----------------------------------------------------------------------- PART III. OTHER HELPFUL SPACE DUEL/GRAVITAR INFORMATION: ---------------------------------------------- SPACE DUEL PINOUTS P20 _______ GND |A | 1| GND +5V |B | 2| +5V |C | 3| +22V |D | 4| -22V +10.3V |E | 5| Lockout |F | 6| Coin Counter Right Coin Counter Left |H | 7| Select LED Start LED |J | 8| Rotate Left 2 Rotate Left 1 |K | 9| Shield 2 Shield 1 |L |10| Thrust 1 Thrust 2 |M |11| Select Switch Switch GND |N |12| Switch GND Switch GND |P |13| Switch GND |R |14| SLAM Switch Coin Aux. |S |15| Self Test |T |16| Coin Switch Left Coin Switch Right |U |17| |V |18| |W |19| |X |20| +5V |Y |21| +5V GND |Z |22| GND ------- P19 _______ X OUT |A | 1| X GND Y OUT |B | 2| Y GND |C | 3| Fire 1 |D | 4| Fire 2 Rotate Right 2 |E | 5| Rotate Right 1 |F | 6| Start Switch Red GND |H | 7| Red Green GND |J | 8| Green Blue GND |K | 9| Blue |L |10| Audio GND |M |11| Audio 2 |N |12| Audio 1 ------- -------------------------------------------------- GRAVITAR PINOUTS P20 _______ GND |A | 1| GND +5V |B | 2| +5V |C | 3| +22V |D | 4| -22V +10.3V |E | 5| Lockout |F | 6| Coin Counter Right Coin Counter Left |H | 7| Player 1 LED Player 2 LED |J | 8| |K | 9| |L |10| Coin Switch Left Start 1 |M |11| Start 2 Switch GND |N |12| Switch GND Switch GND |P |13| Switch GND |R |14| SLAM Switch Coin Aux. |S |15| Self Test |T |16| Coin Switch Left Coin Switch Right |U |17| |V |18| |W |19| |X |20| +5V |Y |21| +5V GND |Z |22| GND ------- P19 _______ X OUT |A | 1| X GND Y OUT |B | 2| Y GND |C | 3| Shields |D | 4| Fire Rotate Left |E | 5| Rotate Right |F | 6| Thrust Red GND |H | 7| Red Green GND |J | 8| Green Blue GND |K | 9| Blue |L |10| Audio GND |M |11| Audio 2 |N |12| Audio 1 ------- -------------------------------------------------- SPACE DUEL CONTROL PANEL PINOUTS pin color function --- ---- ---------- 1 W-Bk Shields 2 2 W-Bn Rotate Left 2 3 W-R Rotate Right 2 4 W-Or Thrust 2 5 W-Y Fire 2 6 W-Gn Select LED 7 W-Bu Select Switch 8 W-V Rotate Left 1 9 W-Gy Rotate Right 1 10 Bn Thrust 1 11 Or Fire 1 12 Gn Shields 1 13 Bu Start LED 14 V Start Switch 15 unused 16 unused 17 unused 18 unused 19 unused 20 unused 21 Bk Switch GND 1 22 Bk Switch GND 2 23 R +5V 24 Gn GND -------------------------------------------------- GRAVITAR CONTROL PANEL PINOUTS pin color function --- ---- ---------- 1 W-Bk Start 2 LED 2 Bu Start 2 Switch 3 W Rotate Left 4 O Rotate Right 5 Y Thrust 6 Gn Fire 7 Bu Shields 8 V Start 1 LED 9 Gy Start 1 Switch 10 Bk Switch GND 11 R +5V 12 Gn GND --------------------------------------------------------- Color Key: Bk Black Gy Gray V Violet Bu Blue O Orange Y Yellow Gn Green R Red W White Bn Brown Colors such as "W-Bk" indicate "solid_color-stripe_color" (in this case, a white wire with a black stripe.) --------------------------------------------------------- from Jess Askey: If you look at the edge connector on the [Gravitar] PCB you will see that the +5V pins and the 'sense' pins are the same. The purpose of the sense pins is to provide a very low current path from the +5V on the PCB back to the power supply. Because the path is low current, the possibility of a voltage drop across the pin connection and wire is extremely small, whereas the potential for a voltage drop across the pin connection on the main +5V wire is much greater. That way, if there is a perfect 5.00V coming out of the Aud/Reg II board and there is a voltage drop of .25V on the main +5V pins, that would put 4.75V on the game PCB, the sense wire sends this voltage back to the Aud/RegII board and it compares it to a reference of +5V. Since it is low, the Aud/Reg II board will theoretically put out a new adjusted voltage of 5.25V so that with the voltage drop taken into consideration, the PCB now has a perfect 5.00V as it should. Sorry for the long-winded explanation. Basically, you can see if you look at the PCB pinouts, the symmetrical connection pattern of the power supply pins. You can even plug it in backwards and the way Atari made it, you most likely will not do any damage! Nice! Just for clarity... the only main difference between Space Duel and Gravitar hardware is the existence of Linear Scaling on Gravitar (not counting that the memory map is a bit different). ----------------------------------------------------------------- | END | -----------------------------------------------------------------