Expert Cartridge

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Expert Cartridge Screenshots
Expert Cartridge Screenshots
Technical Info
RAM 8 kbyte
Hardware features 1 tri-state Switch PRG/OFF/ON

1 button RESET and
optionally (later default on cart):

1 button FREEZE (E.S.M.)
Manual See Binaries Section

Too much to list here.

Check Expert_Cartridge Category for even more!
Programming See Tech Section

Expert Cartridge by the english company Trilogic came in the middle of 1986 relatively late to the european market but got into quite a success story due to its excellent software. Expert Cartridge is a RAM only cartridge carrying 8 kbyte of RAM which can be pre-programmed just like an ISEPIC. The difference apart from the larger available RAM is that it was relatively easy to change the software and add own functionality. LOADing the software of course takes some time but developers added speed loaders whereever possible and suitable and of course the loaded operating system is reset-proof. The name Expert fits pretty well since all of the software if really targetted to be used by the experienced user.

Expert Cartridge opened

On initial release of the hardware just a C64 only version was available quickly being followed by a C128 compatible version. Just a few months later Trilogic started offering an add-on cartridge going by the name of E.S.M. and included this functionality into the most recent cartridge edition. So after about six to nine months all Expert Cardridge sales went with ESM included.

No explanation for the meaning of ESM / E.S.M. could be found as of yet but the importance of a freeze button nobody will deny and ESM delivers just that with a shiny LED added. Users without ESM will have to hit RESTORE to gain access to the monitor mode (which represents the Freezer).

Starting with version 3 of the software Trilogic was not the only apparent name on the product anymore. Cat & Korsh International somewhat took over distribution and the company name was placed within the software. Some production runs of the cartridge have the Trilogic logo removed completely but Trilogic remained in the UK the original and as the company advertising the Expert in the UK. In German the Expert Cartridge was available from REX Datentechnik as well. Check the Expert Cartridge category for full footage.

The main software features the freeze functionality, the monitor which for some modules has commands replaced as well as fast serial IO routines. Flipping the switch when loading in new software for a desired feature and often having the reload the victim software might sound horrible nowadays but as previously stated a lot of people were attracted by the flexibility this RAM based approach offered.

Along with the pretty excessive manual this cartridge was for a long time a perfect aid for the serious developer and a great weapon for the reverse engineering fraction.

This Australia advert carries a note "Australia made" which raised some laughter but obviously needs to be distinguished from "Australia developed" - nice marketing. Rex Datentechnik produced a clone for the german market as pictures. The article below from Your Commdore Issue 48, September 1988 is simply dumped here since it gives a few more infos:


 - Draven for the incredible Expertise - Expert User Club Newsletter collection and adding to the binaries. Check the Expert Cartridge Category.
 - iAN Cook for the OMAlfred software. So far we just figured that OMAlfred was more or less famous for clones in Italy.
 - Zero-X for typing in the Memory Restorer - and even more than required :)
Expert Cartridge Advert 05/1986
Expert Cartridge Advert
Your Commodore Issue 20, 05/1986
Expert Cartridge Advert 12/1986
Expert Cartridge Advert
Your Commodore Issue 27, 12/1986
Your Commodore Issue 48 1988 Sep Expert Piracy.jpg

Expert Cartridge 3.5 Netherlands.jpgExpert Cartridge closed top.jpgExpert Cartridge Utilities Disk small.jpg

As you can see there are lots of pictures and little information or words to utter on the Expert Cartridge itself. The software speaks for itself but whenever you have things to add - please let us know.


As usual the following was shamelessly copied off the expert.c from the VICE emulator:

Expert Competition Your Commodore Issue 47 1988 Aug 8.jpg
    - one 8K RAM (!) bank
    - IO1 seems to be connected to a flipflop, which makes a single bit "register".
      wether it is decoded fully or mirrored over the full IO1 range is unknown
      (the software only uses $de00).
      - any access to io1 toggles the flipflop, which means enabling or disabling
        the cartridge RAM, ie ROMH (exrom) (?)
      - any access to io1 seems to disable write-access to the RAM

    the cartridge has a 3 way switch:


      - NMI logic and registers are disabled
      - RAM is mapped to 8000 (writeable) in 8k game mode


    - after switching from OFF to ON
      - NMI logic is active. the "freezer" can now be activated by either
        pressing restore or the freezer button.
      - Io1 "register" logic is disabled
      - RAM not mapped

    - after reset:
      - RAM is mapped to 8000 (writeable) and E000 (read only) in ultimax mode
      - Io1 "register" logic is enabled (?)

    - on NMI (restore or freezer button pressed):
      - RAM is mapped to 8000 (writeable) and E000 (read only) in ultimax mode
      - Io1 "register" logic is enabled


      - NMI logic and registers are disabled
      - RAM not mapped
      - according to the documentation, the cartridge is disabled. however,
        the NMI logic of the cart still seems to interfer somehow and makes
        some program misbehave. the solution for this was to put an additional
        switch at the NMI line of the cartridge port, which then allows to
        completely disable the cartridge for real.

        this misbehavior is NOT emulated

    there also was an "upgrade" to the hardware at some point, called "EMS".
    this pretty much was no more no less than a freezer button :=)

    short instructions:

    note: the state of the switch and the order of doing things is very important,
          making a mistake here will almost certainly cause it not to work as
          expected. also, since the software tracks its state internally to act
          accordingly, saving it will not result in a runable image at any time.

    preparing the expert ram (skip this if you use a crt file)

    - switch to OFF
    - reset
    - switch to PRG
    - load and run the install software
    - switch to ON (as beeing told on screen)
    - reset. this will usually start some menu/intro screen
    - space to go to monitor

    using the freezer / monitor

    - "pp" or "p" clears memory (and will reset)
    - (if you want to save a crt file for later use, do that now)
    - switch to OFF
    - reset
    - load and run game
    - switch to ON
    - hit restore (or freezer button)
    - z "name" to save backup
    - r to restart running program


  • 1.x (One Point) Software
  • Any missing Trilogic Disk releases and any missing custom hacks


Expert_Cartridge_binaries_rr.c64.org_2021-02.rar contains just the C64 binaries:

  • Trilogic (Cat & Korsh) originally supplied software:
    • v2.5-v2.9 likely not original but at least has lost 2.5 and 2.6 versions
    • v2.7 stock, "d" and "m" (whatever that means, someone compare them) - disk includes v2.8 stock
    • v2.9 stock - coming with 2.7m again
    • v2.10 disk has added quite a few new things: Immortaliser, Sprite Editor, Sprite Extractor and Screen Grabber being some of them
    • v3.1 two versions. One by Trilogic and one by Cat&Korsh
    • v3.2
    • v3.2r got the Rocket Turboloader added - said to be the Expert answer to Warp25. See the test in Your Commodore Issue 47
    • v3.5
    • v4.1 is trying to integrate the software on a more modular base. See also Expert v4.1 software announcement
    • v4.1r
    • v4.2 comes with two disk sides. First one has a new expert v4.2 menu and the second disk has the instructions on the disk to print.
  • Trilogic Utility Disk 2.10 MOS
  • Trilogic Utility Disk 3.2 MOS
  • Turbo Utility for use with Expert Cartridge by Relax ("Fastload ROM" one could say)

Expert_Cartridge_all_rr.c64.org_2021-02.rar contains:


  • The 2.10 software for Expert Cartridge was written by John Twiddy