The Commodore 64's operating system has many shortcomings. Storage devices are really slow, you often have to type unformfortable difficult commands, there exists machine code monitor, the list is long. However, the operating system of the C64 is quite extensible and quickly after the C64 did appear on the market, cartridges started to appear that did fix its shortcomings. These cartridges did offer fastloaders, BASIC extensions, game trainers, freezers and whatever feature for the C64's operating system you could think of. These cartridges are know as utility cartridges by C64 users.

The Final Cartridge III became available when the sophisticatedness of utility cartridges did reach its peak in the 80s. The Final Cartridge III had the first widely used out-of-order fastloader, that could speed up a simple 1541 floppy drive no less than 15 times. It added the ability to scroll in BASIC, a feature that many consider so usefull that they consider it a killer feature which alone is enough to use the FC3. The FC3 has has one of the best machine code monitors, useful BASIC extensions, and advanced backup mechanism and an innovative GUI made the FCIII possibily the most advanced utility cartridge in the golden age of the Commodore 64.

The Final Cartridge III 101% is a recreation of the Final Cartridge III at the fundamental level. Unlike earlier clones, it doesn't just replicate the old hardware, but the hardware has been recreated and improved. At the same time, new firmware has been created that improves the cartridge.

The Final Cartridge 101% firmware and hardware are two projects that can be used independently of each other. You can use the Final Cartridge 101% firmware on your favourite FC3 implementation such as for example the VICE emulator, the 1541 Ultimate or the EasyFlash 3. At the same time, you are free to install any firmware on the Final Cartridge III hardware, regardless whether it is the original firmware, the FC3 101% firmware, the FCIII+ firmware, or the GEOS desktop firmware. The choice is yours.

Final Cartridge 101% firmware

Final Cartridge 101% firmware is an improved firmware for the Final Cartridge III. The Final Cartridge III still is a highly useful cartridge to use with a C64 in the 21st century. However, 21st century use of the C64 differs differs in some ways to how the C64 was used in the 80s:

But on the other hand: The Final Cartridge III 101% firmware adds many subtle but useful improvements to the Final Cartridge III. Some highlights are: For a full description of changes, please read this document: changes.txt

Final Cartridge III 101% firmware is compatible with any Final Cartridge III implementation. You can use of the many clones you can find on the internet, use the 1541 Ultimate, EasyFlash 3, Kung Fu Flash or run it in an emulator. However, using the Final Cartridge III 101% has the advantage that the cartridge is flashable from the Commodore 64 itself, so you can simply upgrade the firmware from diskette.

It is not ruled out that future firmware will require the Final Cartridge III 101% hardware.

Please download The Cartridge III 101% firmware here:

Final Cartridge III 101% hardware

The Final Cartridge III 101% is a flashable cartridge that allows you to install your own firmware on the cartridge. In fact, you must install firmware yourself before you can use it. For example, you can install the original firmware, the Final Cartridge III+ firmware, or my improved firmware. GEOS instead of the FC3 desktop? No problem. And of course you can decide to install another firmware anytime you wish.
Note that The Final Cartridge III is one of the few utility cartridges for which source code is available. However, until now, unless you built your own cartridge it wasn't that easy to use modified firmware. With the flash capability of The Final Cartridge III 101%, the availability of source code becomes much more useful!

The Final Cartridge III 101% hardware offers the following improvements over the original hardware:

Flash utility

The Final Cartridge III 101% hardware is a flashable cartridge. In fact, it doesn't come with cartridge firmware installed, you have to install the firmware of your choice yourself. You can find original and alternative firmwares for your Final Cartridge III 101% on

Reconstructed manual

I am working on a reconstruction of the manual for the Final Cartridge III. This manual is at the moment available in the following languages:

Github project

I am developing the Final Cartridge III 101% on Github:

Schematics and design

The Final Cartridge III 101% consists of just 3 chips: A 256KB flash ROM, a 74HC273 register and the FC3 controller. A simple boost converter built from discrete components can generate a 12V programming voltage for the flash ROM.

The FC3 controller is a GreenPAK SLG46620. GreenPAK is a series of programmable chips from Renesas. These chips are not very comparable to existing programmable chips, they work differently from GALs, CPLDs and FPGAs, but they have an internal logic circuit inside. The FC3 101% can be considered a test how suitable these chips are to build hardware for retro computers and the results are very positive.

Download the schematics and controller chip design:

Obtaining a cartridge

I am selling the Final Cartridge III 101% cartridge on SellMyRetro. The cartridge is pre-assembled. Because an utility cartridge is plugged in and removed many times, the cartridge comes on a gold plated (ENIG) PCB for durability. The cartridge also comes with a cartridge case.

Please make your choice:

FC3 101% cartridge

It is not mandatory to use Sell My Retro, if you don't like to create an account there. If you would like to buy directly, fill in the following form:
E-mail address:
How many Final Cartridge 101% would you like to buy:
€30.00 per piece (assembled, cartridge case is included)
Your postal address:
(if you have a personal comment, you can write that here as well):
Shipment costs are at the moment €5 within EU, €6,50 Europe non-EU and €11 rest of the world. I will normally send a payment request via Paypal (or Tikkie when in the Netherlands). If you would like to pay through IBAN bank transfer, please mention.


Do you have any questions or would you like to contact me for some other reason? You can e-mail me at daniel.mantione at freepascal dot org, or use the following form:
E-mail address:
Your message:


Many thanks to the designers of the original Final Cartridge III:

The Final Cartridge III firmware is copyrighted material of the original creators. The Final Cartridge 101% firmware is a modification of the original firmware and therebound bound by copyright of the original creators. This project is for the benefit of the 21th century Commodore 64 community and meant to preserve and enhance The Final Cartridge III.

The Final Cartridge III 101% hardware is radically different from the original hardware and therefore not affected by original copyrights.

(C) 2021 by DaniŽl Mantione

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