... or a short story about how I've made a small batch of EF3s ;)


Some time ago, I've received new tools that will help with soldering high-quality products.

Precision soldering station ...

aaaand extreeme HotAir station

soooo ...

... to start some seeriuz workz!


Armed with proper tools, I was able to start the new project.
Obviously, it was quite a while ago (a year prolly) but I am writing about it now - yeah I know, post lagging sucks.
It started when Bart030 sent me a link to an awesome cartridge project for C64 - EasyFlash by Skoe. I assure you, that is an excellent cartridge and I would like to thank an author for his work. I hope to meet him someday and thank him in person.

Here is a short description of what this cart does and how it can be used.

I've decided I'll give it a go so I've ordered some PCBs and all needed parts.
Below is a short photo story of an assembly process.

0603s FTW!

Time to solder on flash chips.

Mandatory USB Camera inspection after soldering.

CPLD and FTDI time !

Inspection again.

Ok, the first batch ready.
Here are pics before and after cleaning in an IPA and acetone solution.

I also did a second round with laser cut stencil just to compare assembly time.
Obviously, that was a much quicker way.

Uploading firmware

Here is a video that shows a process of CPLD programming.
It is simply done via simple USB cable, however, cart needs power and that is why it is connected to a C64 mainboard.

All TDO outputs matched ... means that everything went fine ... so far ;)
However, another part is a bit tricky and shows if it was really ok.
Easyprog has to be loaded to C64 while a cart is plugged.
I usually use SD2IEC to get it loaded and once it loads, it performs simple diag which sometimes outputs stuff like below ;)

I usually sort it out by resoldering FLASH and RAM chips. Sometimes, some pins on a CPLD has a poor connection or are simply bridged. That rarely happens but after several drinks, it is very easy to miss such mistakes :D

Anyway, most of the time it is alright and looks like this.

That is a time when a "System area" image can be loaded onto a cart.
Here is how this procedure looks.

That's it! Works like a charm.

Most likely I will do another round of these awesome carts.
At the moment I have few left so I've put it into an online store https://www.retro-cloud.eu/
Online store requires more work and yes I am aware of it ;P

PS. It is also an excellent tool to diagnose broken C64 boards if combined with proper cart image ;)

PS2. Big thanks to Willy/Lamers for solving my problem with resistor networks ;)