This version is pinout compatible with A1200 mainboard revision 1D* only. Variant for 2B mainboard revision is available here.
Installation in a few easy steps:
- remove chassis screws, separate top half og the chassis from bottom by lifting it up
- disconnect LED module from mainboard
- disconnect and remove keyboard assembly. be easy on connector!
- unplug, unscrew and remove floppy drive (GOEX, Gotek,…)
- unscrew mainboard assembly, remove it carefully from the chassis
- unscrew mouse connector from EMI shielding, unlug its extension cable from mainboard
- plug in Centuriontech USB module instead.
IMPORTANT: Make sure pin 1 on USB module pigtail connector, marked with “I” symbol, connects to pin 1 of motherboard mouse port pinheader. Plugging pigtail cable incorrectly will most likely kill your USB module instantly.
- secure the mainboard and USB module bard to the chassis
- return and plug back keyboard, floppy drive port device and LED module
- screw both parts of the chassis back together.
- connect your favourite USB mouse, fire up your A1200 and enjoy all the comfort.
NOTE: The USB mouse module is powered from CN1 port header of your Amiga mainboard through R352 resistor, which in original configuration serves as basic short circuit protection. Under the load, this resistor inevitably creates slight voltage drop on a VCC. As long as your system is powered from well performing PSU and you do not over-stress USB port, this is perfectly fine. However, in the corner cases the voltage can drop bellow minimum threshold level, which causes USB module and/or USB device to shut off. In such a case, you are advised either to replace the PSU for one with better characteristics, or replace above mentioned 4R7 resistor with 0R value. USB module itself contains its own level of short circuit protection – a resettable polymer fuse.
Amiga1200 USB board is based on unmodified SmallyMouse2 design by all great Simon Inns. All the files, schematics and firmware sources can be obtained directly from https://github.com/simoninns/SmallyMouse2