************************************************************************* * * * Amiga KickSwitch for A500 * * * * by * * * * Arlé Mooldijk * * * * © 1993-1996 * * * * release 7-Oct-1996 * * * ************************************************************************* What is it ? ~~~~~~~~~~~~ This Amiga KickSwitch is an automatic switch which makes it possible to toggle between two kickstarts, without the need to turn off your Amiga. Switching is done by holding the reset buttons for a few seconds. It can ONLY be used in an Amiga 500, A600 (not tested) and A2000 (not tested). It is for 16 bit-ROMs only. It has been used in an A500 for over 3 years now, without any problems. What is included in this archive ? ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ - This file... (KickSwitch.txt) - A little .readme file (KickSwitch.readme) - Schematic of the switch (Schematic.iff) - Drawing of the switch (KickSwitch.iff) - Scan of the PCB layout (PCB_Kick.iff) (should be avoided for making a print, it *can* be used to make a PCB, *if* it's cleaned up) - printerdump for EpsonQ compatible printers (Epson_?.prt) - printerdump for HP Laserprinters (HPLaser_?.prt) - PostScript file for PostScript printers (Underside.ps, Upperside.ps and Components.ps) How do you get a print of the PCB ? ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ If you want to make a print of the PCB layout I advise you to use one of the printerdumps or the PostScript file. These give a higher quality than the iff-file. - When the printer is connected to an Amiga, type copy prt: in a Shell. - When the printer is connected to a PC, type copy /b lpt1 in DOS. You must use /b because then it will copy the file as a binary to the printer. With this print you can make your own PCB. What you need ? ~~~~~~~~~~~~~~~ - double sided PCB with a minimal size of 58mm x 52mm (you have to make it yourself) - 2x 40 pin DIL IC sockets (PRECI-DIP) with bus contacts - IC 4060 (IC1) - IC 74HC(T)73 (IC2) (I used a 74HCT73 myself) - resistor 10kOhm - resistor 33kOhm - Multiturn resistor 100kOhm - capacitor MKT 100nF - capacitor Ceramic or Multilayer 100nF - miniclip - 40-pin flatcable 10cm in length (or longer if you like) - 40p DIP socket (for connecting flatcable to ROM socket on the mother- board). - 40p (2x20) Pin header straight (*) - 40p (2x20) Socket connector (for connecting flatcable to 40p header on PCB) (*) - piece of flexible wire - piece of cardboard 58mm x 52mm (*) these 2 may also be replaced by a 40p (2x20) connector flatcable <->PCB. Instructions ~~~~~~~~~~~~ When you have made the PCB with the supplied design you can take the following steps to build the switch : 1) drill the holes (all 0.7-0.8mm, except the holes for the flatcable connector). BE VERY CAREFUL when doing this, use new drills. 2) protect the PCB with some PCB-spray (solder flux) (i.e. SK10 Kontakt Chemie) Let the PCB dry and after this we continue... IMPORTANT The components come on the upperside of the PCB, where the text is readable ! 3) Solder the IC's (4060 and 74HC(T)73) on the PCB. 4) Then solder the 40p IC socket U1 on the PCB (the inside of this socket needs to be cleared of the middle bar, the IC's have to fit under the socket). *The notch must be on the same side as shown on the PCB.* Solder pins 10, 21 and 30 on both sides of the PCB. 5) Solder the other 40p IC socket (U2) on the PCB. *The notch must be on the same side as shown on the PCB.* Pin 10 needs to be soldered on both sides of the PCB. 6) Solder the resistors and capacitors on the PCB. 7) Connect the 40p DIP socket to the flatcable. BE CAREFUL ! 8) Connect the 40p Socket connector to the flatcable. BE CAREFUL ! 9) Solder the 40p pin header on the PCB or solder the 40p (2x20) connector flatcable<->PCB onto the PCB. BE CAREFUL ! 10) Solder a piece of wire to the PCB on point _KBRESET. 11) Solder the miniclip to the wire. 12) Check all connections and solder points ! 13) Glue a piece cardboard to the underside of the PCB. It must isolate, otherwise it may cause a short-circuit and blow your Amiga :-( When the glue is dry the switch can be build into your Amiga. 14) Put the ROM's (1.3/2.04/3.1) in the sockets on the PCB. *The notch needs to be on the same side as the sockets* In my case the Amiga boots with the ROM in socket U2. 15) Put the 40p DIP socket in the ROM-socket on the motherboard. *The notch needs to be on the same side as the sockets* 16) Connect the flatcable-connector to the PCB. The flatcable doesn't go over the PCB (so the components are still visible). 17) Connect the miniclip to the signal _KBRESET on the motherboard. A500 : Connect the miniclip to pin 3 (seen from the front of A500) of the keyboard-connector. DO NOT short circuit ! The keyboard-plug still can be connected... A2000 : _KBRESET can be found on pin 5 of U102 (Gary). DO NOT short circuit ! 18) Set the Multiturn in the middle position. 19) If everything is connected (and properly isolated) then turn on your Amiga. You must not close it, otherwise you cannot adjust the time needed to change from ROM. 20) If you don't like the ROM verion it starts with then turn off the Amiga and exchange the ROM's U1<->U2 on the PCB... 20) The time can be set by adjusting the Multiturn. It's a way of trial and error...so take some time to adjust... 21) If everything fails switch off your Amiga and recheck everything. 22) If it works ok you may close your Amiga. From then on you can toggle between the ROM's by holding the reset buttons for the time set (in my case 3 seconds). The selected ROM will be active untill you hold the reset buttons for the time set. When you turn off the Amiga it will boot with the normal ROM again. DISCLAIMER ~~~~~~~~~~ THIS PROJECT IS FOR EXPERIENCED PEOPLE ONLY ! YOU DO THIS ENTIRELY AT YOUR OWN RISK ! THE AUTHOR ACCEPTS NO RESPONSIBILITY FOR DAMAGE AND/OR LOSS OF DATA/EQUIPMENT AS A RESULT OF BUILDING THE INTERFACE DESCRIBED IN THIS DOCUMENT. COPYRIGHT ~~~~~~~~~ © 1993-1996 A.L. Mooldijk, The Netherlands The files in this archive may not be altered in any way. Commercial reproduction is prohibited (unless you have my written permission). DISTRIBUTION ~~~~~~~~~~~~ This archive may be freely distributed. It may be put on Aminet, Aminet-CD's, Fred Fish disks, etc... It may also be included on Coverdisks, but then I would like to receive a free copy of the magazine and the disk (it will make me very happy). CREDITS ~~~~~~~ I would like to thank : - Flemming Steffensen, for reading this document and his comments. SUPPORT ~~~~~~~ If you have questions, or suggestions, please mail me... There's one thing I won't do and that's to make PCB's...I don't have the time and equipment to do so... :-( AUTHOR ~~~~~~ Arlé Mooldijk E-mail : amooldyk@tref.nl Snail-mail : A.L. Mooldijk Hein Ewoutsstraat 7 3222 CJ Hellevoetsluis The Netherlands Member of Team AMIGA ************************************************************************* EOF