Joystick/Mouse Adaptor for the CDTV

Copyright 1994-1995, Darren Ewaniuk
Converted to HTML on May 29, 1995

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[Introduction] [Parts List] [Construction] [Pin Diagrams] [Installation] [Notes] [Disclaimer] [Distribution] [Author]


This text will show you how to add standard joystick/mouse ports onto your CDTV at a very low cost. You will need to open up your CDTV to perform this, but you will not need to cut or solder to any components of your CDTV. This adaptor, once you make it up, will consist of a DIP chip socket, two ribbon cables, and the joystick ports themselves. Installation consists of removing a socketed chip from your CDTV motherboard, installing the adaptor's socket in its place, and replacing the chip in the adaptor's socket.

Parts required:


  1. First, cut the ribbon cable into two equal 45 cm (18 inch) lengths. From each cable, remove the tenth conductor (the one on the edge opposite the striped conductor).

  2. Next, put the DE-9 joystick connectors on one end of each of the ribbon cables. The procedure will vary depending on which type of connectors you have. Follow 2.1 if you have ribbon cable connectors, 2.2 if you have solder cup connectors.

    1. If you have IDC ribbon cable connectors, lift up the end cap so you can slide the ribbon cable between it and the connector, or if you cannot do that with the connectors you have, remove the end cap to expose the crimping prongs. Decide whether you want the ribbon up or down, and make up both cables the same way by having the free end of the ribbon cable coming out at the side of the connector with either the wide or narrow side of the 'D' respectively. Align the stripe end of the ribbon cable with the pin 1 prong (pin numbers can be read from the front of the connector where you would normally plug in your mouse). The end of the cable should be flush with the end of the connector. Then place the end cap on top of the ribbon cable if you removed it, and using a vise, clamp, or hammer, squeeze the end cap onto the connector until the clips on the side lock the connector together. Repeat the procedure for the second ribbon cable.

    2. If you have solder cup connectors, split apart all of the wires from one end of each ribbon cable so that they are separated from the other wires for about 12 mm (1/2 inch). Strip the insulation from each of these wires for about 2 mm (1/16 inch) and tin them with solder. Solder the striped wire to pin 1 of the connector (on the upper pins), the second wire to pin 6 (on the lower pins), the third wire to pin 2, etc. as shown in the DE-9 pin diagram. When all 9 pins are soldered, repeat with the other ribbon cable.
        striped wire -> pin 1
        second wire  -> pin 6
        third wire   -> pin 2
        fourth wire  -> pin 7
        fifth wire   -> pin 3
        sixth wire   -> pin 8
        seventh wire -> pin 4
        eighth wire  -> pin 9
        ninth wire   -> pin 5

  3. Prepare the first cable for the mouse port. Split apart all of the wires from the remaining end of the ribbon cable so that they are separated from the other wires for about 50 mm (2 inches). Cut off 25 mm (1 inch) of each wire except for the fourth and sixth wires. Leave the fourth wire long, and cut 13 mm (1/2 inch) from the sixth wire. This will make the connections to the DIP socket tidy. Then strip about 2 mm (1/16 inch) of insulation from each wire, and tin with solder. Solder each wire to the appropriate DIP socket pin, as shown in the DIP socket diagram. Curl each wire around the top, thicker area of the DIP socket pin and solder it using a minimum amount of solder. Then cut off any excess wire. Keep the narrow part of the pins clean of solder so that they can fit in the socket. Ensure that the wires and solder do not touch other pins.

  4. Prepare the second cable for the joystick port. First, split apart the ribbon cable for 75 mm (3 inches). Cut off 50 mm (2 inches) of each wire except for the fourth and sixth wires. Again, leave the fourth wire long, and cut off about 37 mm (1-1/2 inch) from the sixth wire. Strip the wires, tin with solder, and solder the wires to the DIP socket. Note that pin 12 (ground) will have wires from both joystick ports attached to it.

  5. Double-check that the ribbon cable wires are connected to the correct pins on the DE-9 connectors and the DIP socket, and that there are no wires or solder bridges between adjacent pins. Then proceed to the installation step.

Pin diagrams:


       \ 5   4   3   2   1 /
        \  9   8   7   6  /

  pins should be numbered on the
  front and back of the connector

TOP VIEW OF 40 PIN MACHINE PIN DIP SOCKET 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 |o--o--o--o--o--o--o--o--o--o--o--o--o--o--o--o--o--o--o--o| | | |) | | | |o--o--o--o--o--o--o--o--o--o--o--o--o--o--o--o--o--o--o--o| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Note that the end with pin 1 has a notch in it
PARTIAL BOTTOM VIEW OF DIP SOCKET SHOWING WIRE CONNECTIONS | | | | | | | | <- Wire with bare end curled around wide part of pin |o|-o--o|-o|-o|.. |/ / / / <- Cut off excess wire at centre of socket |) | |o--o--o--o--o-.. 40 39 38 37 36
SIDE VIEW OF 40 PIN MACHINE PIN DIP SOCKET Socket holes (don't solder) / [XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX] <- Plastic part of socket # # # # # # # # # # # # # # # # # # # # <- Top part of pins | | | | | | | | | | | | | | | | | | | | (solder here) | | | | | | | | | | | | | | | | | | | | <- Pins (don't solder)
RIBBON CABLE CONNECTION DIAGRAM 9 conductor flat ribbon cable To DE-9 connector pin # To DE-9 connector pin # (Mouse port) (Joystick port) 5 4 3 2 1 5 4 3 2 1 9 8 7 6 9 8 7 6 | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |Stripe | | | | | | | | |Stripe | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 3 4 6 | 7 | 8 5 9 14 15 17 | 18 | 19 16 20 | | | | 12 | 12 | (12 mm | (12 mm | longer) 1 longer) | (25 mm | longer) 30 (50 mm longer) To machine pin DIP socket pin #


  1. Remove all power to the CDTV by unplugging the power cable.

  2. Carefully place your CDTV on a static-free mat, and use a static-free wristband if you have one. If you don't have these, at least do this work on a worktable in a room without a rug after you have grounded yourself.

  3. Open the top cover by unscrewing the four screws in the sides and the two screws in the top back of the CDTV. Once the cover is open, do not touch any components unless told to. Many of the components could be damaged by a static charge, and even with power off, there could be dangerous voltages present on some components.

  4. Find U75, a 40 pin DIP chip at the front centre of the CDTV motherboard. The chip will be marked "252609-02". It may have a different number after the dash, but the first part of the number should be the same. Carefully remove it by prying it up using a flat blade screwdriver from the sides, making sure that you do not bend the pins. Remember the orientation of this chip (the notch on one end should be on the side closest to the right of the CDTV).

  5. Carefully plug the socket of the adaptor cable into the socket you just removed the chip from. Pin 1 of the adaptor socket should be towards the right, so that the ribbon cables exit towards the back of the CDTV.

  6. Replace U75 in the adaptor's socket, keeping it in the same orientation it was when you removed it. Make sure that it is firmly seated and that none of the pins are bent out of the socket.

  7. Route the joystick adaptor cables to a suitable position outside your CDTV. If you do not have a SCSI-TV, then you can route the cables out the expansion connector space. To do this, remove the expansion slot cover by removing the two screws holding it in place, and temporarily remove the ribbon cable at the back left of the CDTV. Now route the two joystick cables through the hole at the back left of the chassis, behind the CD-ROM drive, then out the expansion hole. For a simple strain relief, arrange the connectors so that the ribbon cables exit the top of the expansion hole, then bolt the expansion plate back on so that the top of it holds the ribbon cables in place. If you want to make a professional looking system, then cut or punch out DE-9 holes in the expansion plate and mount the joystick connectors on it. Remember to replace the ribbon cable at the back left of the CDTV when you are finished.

  8. Replace the top cover of the CDTV, securing the four screws on the sides and the two on the back.


  1. This adaptor cable operates just as if you attached a 'Y' cable to the joystick/mouse ports of a normal Amiga. Thus, attaching a mouse to the mouse port may have unexpected effects, since you are effectively putting it and the CDTV remote's 'infrared mouse' in parallel. Because of the way a mouse works, two mice normally cannot share the same port. If you wish to use the CDTV remote in mouse mode, you must remove the mouse from the mouse port. If you wish to use a mouse in the mouse port, you must not move the mouse from the CDTV remote while it is in mouse mode. If you wish to permanently use the mouse in the mouse port, and disable the CDTV infrared controller's mouse mode, then remove U75, bend up pins 6, 7, 8, and 9, and replace it back in the adaptor's socket. This will disable the remote's movements in mouse mode only, while still keeping its joystick functions and mouse buttons intact.

  2. If you wish to use an analog joystick with this adaptor, you may have to remove U75, bend up pins 14 and 15, and replace it in the adaptor's socket.

Warning and Disclaimer:

Installing this adaptor will void your CDTV's warranty, since it requires opening your CDTV's case. There are static sensitive devices and possibly dangerous voltages in your CDTV. Do not touch any components while the cover is open. If this adaptor is put together incorrectly, it may damage your CDTV. Verify that the connections are correct and that there are no solder bridges when constructing the cable, and verify that there are no bent pins or touching pins when installing the adaptor. The builder of this project is responsible for verifying that this project complies with all electrical, safety, radio frequency, or other relevant codes in your region. Neither Darren Ewaniuk, his employer(s), nor any distributors of this text assume any responsibility for any damages whatsoever occurred from the assembly, installation, or use of this project, nor from any effects or damages caused by any design flaws or typographical errors. In other words, it works for me, but if you build it, you're on your own...

CDTV and Amiga are registered trademarks of Commodore Amiga Inc.
SCSI-TV is a trademark of AmiTrix Development.


These designs are Copyright (C) 1994 Darren Ewaniuk, but are freely distributable under the condition that the body of the text is unaltered. Distribution is permitted for electronic distribution via Aminet, BBS'es, and other computer networks, for profit and not-for-profit shareware distributions via CD-ROM or floppy disk, and through magazines, whether in print or on disk. It would be nice though if CD-ROM or magazine publishers let me know if you plan on using this (and a freebie would be greatly appreciated :->). Commercial use to manufacture these adaptors for profit MUST first obtain permission from me.

Author information:

Postal Address: Internet EMail:

Internet Home Page:

I work as an Electrical Engineer in my day job, and like to design stuff for the Amiga as a hobby. I've done some freeware hacks such as this, and also have worked on some Amiga projects for AmiTrix Development.

Please note as above that I assume absolutely no professional responsibility whatsoever for the design, construction, installation, or use of this project.
(Those Engineering Law books made me paranoid :->)

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Darren Ewaniuk,
Last updated May 29, 1995