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]

Introduction:

This text will show you how to add standard joystick/mouse portsonto your CDTV at a very low cost. You will need to open up yourCDTV to perform this, but you will not need to cut or solder to anycomponents of your CDTV. This adaptor, once you make it up, willconsist of a DIP chip socket, two ribbon cables, and the joystickports themselves. Installation consists of removing a socketed chipfrom your CDTV motherboard, installing the adaptor's socket in itsplace, and replacing the chip in the adaptor's socket.

Parts required:

Construction:

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

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

    1. If you have IDC ribbon cable connectors, lift up theend cap so you can slide the ribbon cable between itand the connector, or if you cannot do that with theconnectors you have, remove the end cap to expose thecrimping prongs. Decide whether you want the ribbonup or down, and make up both cables the same way byhaving the free end of the ribbon cable coming out atthe side of the connector with either the wide ornarrow side of the 'D' respectively. Align thestripe end of the ribbon cable with the pin 1 prong(pin numbers can be read from the front of theconnector where you would normally plug in yourmouse). The end of the cable should be flush withthe end of the connector. Then place the end cap ontop of the ribbon cable if you removed it, and usinga vise, clamp, or hammer, squeeze the end cap ontothe connector until the clips on the side lock theconnector together. Repeat the procedure for thesecond ribbon cable.

    2. If you have solder cup connectors, split apart all ofthe wires from one end of each ribbon cable so thatthey are separated from the other wires for about12 mm (1/2 inch). Strip the insulation from each ofthese wires for about 2 mm (1/16 inch) and tin themwith solder. Solder the striped wire to pin 1 ofthe connector (on the upper pins), the second wire topin 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 1second wire  -> pin 6third wire   -> pin 2fourth wire  -> pin 7fifth wire   -> pin 3sixth wire   -> pin 8seventh wire -> pin 4eighth wire  -> pin 9ninth wire   -> pin 5

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

  4. Prepare the second cable for the joystick port. First, splitapart the ribbon cable for 75 mm (3 inches). Cut off 50 mm(2 inches) of each wire except for the fourth and sixthwires. Again, leave the fourth wire long, and cut off about37 mm (1-1/2 inch) from the sixth wire. Strip the wires, tinwith solder, and solder the wires to the DIP socket. Notethat pin 12 (ground) will have wires from both joystick portsattached to it.

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

Pin diagrams:

BACK (SOLDER CUP) VIEW OF MALE DE-9      \---------------------/       \ 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 SOCKET40 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 #

Installation:

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

  2. Carefully place your CDTV on a static-free mat, and usea static-free wristband if you have one. If you don't havethese, at least do this work on a worktable in a room withouta rug after you have grounded yourself.

  3. Open the top cover by unscrewing the four screws in the sidesand the two screws in the top back of the CDTV. Once thecover 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 voltagespresent on some components.

  4. Find U75, a 40 pin DIP chip at the front centre of the CDTVmotherboard. The chip will be marked "252609-02". It mayhave a different number after the dash, but the first part ofthe number should be the same. Carefully remove it by pryingit up using a flat blade screwdriver from the sides, makingsure that you do not bend the pins. Remember the orientationof this chip (the notch on one end should be on the sideclosest to the right of the CDTV).

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

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

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

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

Notes:

  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 unexpectedeffects, since you are effectively putting it and theCDTV remote's 'infrared mouse' in parallel. Because of theway a mouse works, two mice normally cannot share the sameport. If you wish to use the CDTV remote in mouse mode, youmust remove the mouse from the mouse port. If you wish to usea mouse in the mouse port, you must not move the mouse fromthe CDTV remote while it is in mouse mode. If you wish topermanently use the mouse in the mouse port, and disable theCDTV infrared controller's mouse mode, then remove U75, bendup pins 6, 7, 8, and 9, and replace it back in the adaptor'ssocket. This will disable the remote's movements in mousemode only, while still keeping its joystick functions andmouse buttons intact.

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

Warning and Disclaimer:

Installing this adaptor will void your CDTV's warranty, since itrequires opening your CDTV's case. There are static sensitivedevices and possibly dangerous voltages in your CDTV. Do not touchany components while the cover is open. If this adaptor is puttogether incorrectly, it may damage your CDTV. Verify that theconnections are correct and that there are no solder bridges whenconstructing the cable, and verify that there are no bent pins ortouching pins when installing the adaptor. The builder of thisproject is responsible for verifying that this project complies withall electrical, safety, radio frequency, or other relevant codes inyour region. Neither Darren Ewaniuk, his employer(s), nor anydistributors of this text assume any responsibility for any damageswhatsoever occurred from the assembly, installation, or use of thisproject, nor from any effects or damages caused by any design flawsor typographical errors. In other words, it works for me, but ifyou 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.

Distribution:

These designs are Copyright (C) 1994 Darren Ewaniuk, but are freelydistributable under the condition that the body of the text isunaltered. Distribution is permitted for electronic distribution viaAminet, BBS'es, and other computer networks, for profit andnot-for-profit shareware distributions via CD-ROM or floppy disk, andthrough magazines, whether in print or on disk. It would be nicethough if CD-ROM or magazine publishers let me know if you plan onusing this (and a freebie would be greatly appreciated :->).Commercial use to manufacture these adaptors for profit MUST firstobtain permission from me.

About The Author:

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

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

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