Changes
There are several compatible equivalents for both the µPD765 and the 41464 DRAM ICs, which may be easier to source than these originals.
LR04 (The golden coloured ring on the right in the top picture) is used to filter supply spikes from the floppy motors getting back to the main PCB. The original part SN8D-500 is a 125µH filter rated at 2A. [[Image:LR04.jpg|200px|center]]<CENTER>LR04 alternative - 100µH 500mA</CENTER> If you can find this the original part then use it, if not any filter between 100µH and 150µH with a rating of 500mA or more should work fine, especially if you intend connecting a modern 3.5in floppy instead which uses less current than an original 3in Amstrad floppy.
NR01 is a network of 680Ohm resistors in star configuration, this part can be hard to find, but it can be also created with six standard resistors
[[Image:DIYNR101.jpg|300px|center]]
<CENTER>NR01 made from standard resistors</CENTER>
If you are using a proper resistor network component, a white dot on the component marks pin 1 which should be located in the pin nearest the back of the CPC.
== Preparing The PCB ==
You will also notice that there are two black bridge wires running from the top of the PCB down to two of the holes you need to use for
C21 and C23. These connects connections will still be required after the mod, so you will need to remove and later re-connect the bottom end of these wires to the legs of the capacitors. Take note of which wire goes to which capacitor!
Although most of the parts are concentrated around the bottom right area of the PCB, there are a few other parts hidden around the board that need to be added. R28 (Directly behind the analogue joystick port) tells the ASIC that the CPC has 128K instead of 64K. R55 (between the ASIC and first RAM IC) connects the NCAS1 signal to the new RAM. LR04 and C39 (above the 26way floppy header) are required to supply the floppy disk with power. C39 is the only passive component with poles. Make sure that it is soldered in the correct position, with the minus pole towards the rear of the CPC.
