exxos's Atari, Amiga & retro forum

The In-depth technicals of this new patch is discussed in this clock patch investigation thread. Basically this patch offers greater noise immunity,drive currents,voltages and moves away from the classic clock patch approach. The V4 clock patch is more in-depth fitting than the older designs as it fixes more problems now they are known and investigated.

The V4clock patch comprises of two parts. The second part which solders over the Ajax is intended for experimental with overclocking more than anything. While you can fit this without a bus speed it is generally not necessary.

NOTE - The adjustable delay is no longer on the standard clock patch board. It has been moved over to the "part 2" board which gives 10ns steps delays and further cleans up and buffers the clock line.

This installs much like the previous V2 clock patch. Where the clock patch is soldered on top of the GAL.

Solder wires as illustrated below. I have colour-coded these to try make things simpler to understand.


In order to solve clock issues on the FPU, a 100pF is soldered on the bottom of the motherboard as illustrated below.


The SDMA clock end requires a 68R resistor in the clock line and a 22pF capacitor from the right side of the resistor to the AJAX GND.

I strongly recommend a magnifier for doing this work and I also strongly recommend not attempting this yourself unless you are good at soldering!

Firstly cut the "boot-leg" track. Then carefully remove the solder resist with a fibre panel similar. Tinplate/prime the track with solder.


NOTE - If you are fitting the "part 2" board then you skip the capacitor and resistor fitting as illustrated below and you directly to the next post for fitting the part two patch board.

Take a 0603 68R resistor and solder it has below. I used solder paste and a gas soldering iron on the lowest setting.

While you can do this with a soldering iron it is extremely difficult as the resistor normally sticks to the soldering iron tip! As such, I do not recommend this approach!


Then solder the 22pF capacitor as shown below. Be careful not to shorted against the via's which are close by!



NOTE - Currently this patch is not publicly available yet as it is in beta testing.

Falcon clock patch V4 - PART 2 board.

This board has been carefully designed to allow proper experimentation with bus speeders by allowing delays in steps of 10ns. This board is simple to fit even though it by itself looks complicated (and it is for various reasons as illustrated in the investigation thread).

(Apologies for the out of focus image. I will try and take a better one for my new boards arrive. )


The board just simply solders on top of the Ajax.

Basically the left-hand side of the cut track goes to the add-on board's "IN" pad. then the right-hand side of the cut track (SDMA side) goes to one of the pads across the top of the board. These are arranged in 10ns steps. Namely 0ns,10ns,20ns,30ns,40ns.