The starting point was an article from AMIIGA MAGAZINE 11/1992 http://www.a1k.org/a1000/hardware/kickswitch/kickswitch.php by Harald Ziegler.

When I started the project i realised that it would be easy to add bootselector as well. I already had one that was built basing on instructions from http://circuit-board.de/forum/index.php/Thread/11481-Amiga-Boot-Selector-f%C3%BCr-500-1000-2000/ page, so I knew that it's easy, just to reverse pins 13-14 on CIA chip. With that you can use for example USB Gotek drive in external enclosure as DF0.

Because of adding CIA chip on the board, the redesign of orignal project was not so easy as I thought at the beginnig...but I managed:). In opposite to original project I have also added one 4,7kOhm resistor (R1) coupled with Pin 21 of Kickstart ROM socket, so there is no need to connect Pin 1 with Pin 20 of U3J 74LS373 chip (simply connect Pin 1 of U3J to Pin 1 JP2 on kickstart adapter).

amiga-1000-ks-adaptor-pcb

circuit board

amiga-1000-adaptor-4-2-2

assembled adapter

 amiga-1000-ks-adaptor-inside
amiga-1000-floppy 

kickstart adapter inside Amiga 1000, as you can see there is no conflict with floppy disk drive

amiga-1000-ks31

it's working!:)

 

Please note, that if you're using KS ROM 1.2, 1.3 or 2.05 there are no additional modifications required, but if you're using KS ROM 3.1 or multirom you have to connect PIN 21 with PIN 31 by a wire.

amiga-1000-ks31-adaptor--back

Some videos as well...

AMIGA 1000 without Piggyboard kickstart adaptor with bootselector installation:

Note that some soldering skills are required. If you're not familiar with soldering, than it's better to find a person to help, than to destroy our priceless AMIGA! Also some desoldering tools are recommended to remove existing solder from U5R before we can solder a socket to U5R. Let's start.

  • First you have to solder a 28-pin socket to position U5R on the mainboard.

ks-adapter-install-1

  • Next step is to change a jumpers on positionf W2 and W4 as shown below (you wille have to cut some traces). I have added jumpers, just to be able to reverse changes if needed.

amiga w-cut

ks-adapter-install-2

 

 

ks-adapter-install-3

  • Next you have to cut the conductor path between PAL DAUGCAS position U6N Pin 17 and 74LS373 position U3J Pin 1. Alternative you can cut Pin 17 of PAL DAUGCAS so it has no contact to the board.

 

  • Now you have to solder one wire from 74LS373 position U3J Pin 1 to the Kickstart Adapter JP2 Pin 1 - this will deactive 256kb WOM (Write Once Memory) area.

 ks-adapter-inside-amiga-1000-5

  • Finally you have to solder two wires, one wire from PAL DAUGCAS position U6N Pin 2 to the Kickstart Adapter JP2 Pin 2, the second wire from PAL DAUGCAS position U6N Pin 9 to the Kickstart Adapter JP2 Pin 3.

 ks-adapter-inside-amiga-1000-6

  • Now you are ready to fit the Kickstart Adapter into position U5S, U5R and U6S 8250 on the mainboard.

 ks-adapter-inside-amiga-1000-4

Before installing a Kickstart ROM and switching on the Amiga please double check all steps. If you are using newer Kickstart ROM chip and it will not work try to conduct Pin 21 and Pin 31 of Kickstart ROM like described below.

http://www.area536.com/projects/amiga/upgrade-amiga-500-kickstart-from-12-to-31/

 

 

Copyright@2017 Arkadiusz Neubauer

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